Other Activities before Davening
In general, one should not begin an activity which will require of one to become engaged in it, before performing a mitzvah at hand. When it comes to davening specifically, there are unique stringencies and leniences for each of the davenings as detailed below.
- There is a positive aspect to learning before davening to prepare oneself for davening. 
- If one usually goes to daven in a minyan which is at a set time, then it is permissible to learn before davening even after Olot HaShachar and so, the minhag is to learn before davening. 
- It is permissible to learn until Olot HaShachar. However, once Olot Hashachar comes, it is forbidden to begin learning until one has prayed. Some are lenient to permit learning after Olot HaShachar until close to HaNetz HaChama. Nonetheless, it is permissible to learn even after Olot Hashachar in any of the following three circumstances:
- if one is learning in the place where a tzibbur will come to daven, 
- if one asked a friend who was not learning to remind one to daven before the latest time of Shema and Tefilla,  or
- if one was teaching Torah to a group or is learning in a group and if there is no concern that one will miss the latest time for Shema. 
- Some add that it is permissible if one is not learning in-depth. 
- If one already began learning before Olot HaShachar, one should continue and does not have to stop. If one began learning after Olot HaShachar, some say that one should stop for Kriyat Shema and some say that one does not have to stop as long as there is time prior to the latest time for Shema. 
- Someone who can not learn after Olot HaShachar and the tzibbur is only davening later, it is preferable for them to daven earlier and then learn even though one will not be davening together at the time of the tzibbur. 
- It is forbidden to do work after Olot HaShachar until one has prayed. From a half hour before Olot HaShachar it is preferable to say Birchot HaShachar before working.  However, work for a mitzvah is permissible 
- If one began working prior to Olot HaShachar it is permissible to continue afterwards. 
- One may take out the garbage on one's way to Shul before davening.
- It is permitted to do an activity which is a mitzvah before davening.  In some contexts, it may only be permitted if one can not do that mitzvah after davening and also that one should say Kriyat Shema before that activity. 
- Generally speaking, it is forbidden to travel before davening even if one knows that he will be able to daven upon arrival.
- Traveling is usually defined by being on the road for a minimum of 72 minutes, and some say that this is true here as well: only a trip that would take 72 minutes or more would one be prohibited to make before davening. However, some say that even a shorter trip is consiered ‘traveling’ and would be prohibited (if not taken to get to one’s usual place of davening).
- Some say that even traveling for the purposes of doing a mitzvah is prohibited although most disagree and say that it would be permissible to travel before davening to perform a mitzvah, and even in order to daven better or to daven at the Kosel Hamaaravi.
- If traveling will be sufficiently easier if done before davening (for example, in a case where, if one were to wait until after davening, there will much more traffic on the roads and the trip will take much more time), some permit traveling before davening, especially if waiting would cause someone to miss a bus or otherwise not be able to travel at all.
- In all of the cases in which traveling before davening is permissible, it is still better to say the birkos hashachar before one embarks on his or her travels.
- The prohibition of traveling before Shacharis applies beginning from Alos Hashachar. although some say that it begins from half an hour beforehand.
- If one stayed up all night, then it is forbidden to go to sleep within a half hour before Olot HaShachar until one has prayed. If one asks a friend who already slept that night to wake one up then it is permissible. If one can not ask a friend and one can not pray, one may be lenient and just say Kriyat Shema and then go to sleep. 
- If one was sleeping and woke up to go to the bathroom one may go back to sleep even after Olot HaShachar as long as one will not miss the latest time for Shema. 
- It is permissible to go to the bathhouse or cut one's hair until Olot HaShachar but afterwards one may not start to go to the bathhouse or cut one's hair.  However, a short shower with a little soap for someone who feels unclean in order to prepare for davening is permissible. 
- It is permissible to go to the mikveh after Olot HaShachar prior to praying 
- Prior to davening one should not pick up a child which may soil itself, or begin to cry when one puts it down and by the time one cleans up or appeases the child one may have missed the time for davening. 
- One should give tzedaka before praying.
- It is permissible to learn until Mincha Ketana (9½ hours into the day). However, once Mincha Ketana comes, it is forbidden to learn until one prays.  Nonetheless, under four circumstances it is permissible to learn even after Mincha Ketana:
- if one usually goes to daven in a tzibbur (minyan),
- if one is learning in the place where a tzibbur will come to daven,
- if one asked a friend who was not learning to remind one before the latest time of Mincha, or
- if one was teaching Torah to a group and if there is no concern that one will miss the latest time for Mincha. 
- From 9 hours in the day, one may not start work that could drag on and make one miss the time for Mincha. If one always goes to minyan and there is a set time, it is permissible, even after 9½ hours. 
Traveling, Showering, Shaving
- Most poskim assume that the prohibition of traveling also applies to traveling before one davens Mincha or Maariv, although the custom is to be more lenient regarding Minchah and Maariv for someone who would anyway be waiting for the usually scheduled minyan or for Minchah Ketanah.
- If one always goes to minyan at a set time, it is permissible to shower and shave even after 9½ hours. 
- One should not sleep after 9½ hours. If one asks a friend to wake one up, then it is permissible. 
- It is permissible to learn until Tzet HaKochavim. However, once Tzet HaKochavim comes, it is forbidden to learn until one has prayed.  Nonetheless, under two circumstances it is permissible to learn even after Tzet HaKochavim:
Working, Traveling, Showering, Shaving
- If one always goes to minyan and there is a set time, it is permissible to work, travel, shower, and shave, even after Tzet HaKochavim. 
- One should not sleep within a half hour of Tzet HaChachavim. Asks a friend to wake one up only works at a time when people are not going to sleep and the friend is reliable. 
- Piskei Teshuvot 89:23. See there where he writes that the minhag is to be lenient to learn before davening because of the positive aspect of learning before davening.
- S”A 89:6, Piskei Teshuvot 89:23
- S”A 89:6
- Mishna Brurah 89:31
- Mishna Brurah 89:32
- Mishna Brurah 89:34. See the collolary to this for Kriyat Shema Arvit in Mishna Brurah 235:17.
- Shulchan Aruch 89:6 permits davening later if one is teaching a group. Mishna Brurah 89:35 says that this is only if there is no concern for missing Shema. Ishei Yisrael 13:34 in the name of Mekor Chaim 89:6 includes the case of learning in a group.
- Piskei Teshuvot 89:23 quoting Sh”t Avnei Tzedek 19 (however, see Mishna Brurah 89:33 who implies the opposite).
- Mishna Brurah 89:30
- Mishna Brurah 89:33
- Mishna Brurah 89:37, Ishei Yisrael 13:18
- Ishei Yisrael 13:19
- Mishna Brurah 70:23-5, Ishei Yisrael 13:22
- Rav Shlomo Zalman Auerbach (quoted by Tefillah Kehilchata c. 6, n. 36 and Ishei Yisrael c. 13, n. 46, p. 122) ruled that it is permitted to quickly look over a newspaper, take out the trash on one's way to Shul, or put a load of sorted laundry into the washer before davening. See also Eshel Avraham 89:3 who says that perhaps anything which is a quick and simple task which would be permitted on Chol HaMoed would be permitted before davening.
- Ishrei Yisrael (p. 122). A strong proof is: Rashi (Megillah 23a s.v. BeYom Tov), Mishna Brurah 529:14
- Mishna Brurah 250:1
- Brachos 14a as understood by Rosh Brachos 1:7, Rif 8a, and Beis Yosef 89
- Mishnah Berurah 89:20, see also Mishnah Berurah 90:53
- Shut Ohr Letzion 2:32
- See Halichos Shlomo Tefillah 2:11:14 who writes that even taking a short and easy trip before davening is prohibited.
- Shut Divrei Yatziv O.C. #8
- Pri Chadash 89:6, Pri Megadim (Eishel Avraham) 89:15, Aruch Hashulchan 89:22, Mishnah Berurah 90:53
- Piskei Teshuvot 89:16
- Or Letzion vol 2, Yalkut Yosef 89:29 (pg 94 in ed. 5764)
- Shut Shevet Halevi 8:19, although Shut Divrei Yatziv O.C. 8 would likely disagree with this leniency
- Magen Avraham 89:10, Aruch Hashulchan 89:22, Leket Hakemach 89:37 quoted in Dirshu edition of the Mishnah Berurah, Siman 89 note 24. Needless to say, one must still make sure to daven and say Keriyas Shema before too late in the morning.
- Rama 89:3 quotes an opinion to the effect that traveling is always permitted after making brachos, although Aruch Hashulchan 89:21 points out that there is in fact no such legitimate opinion. Nonetheless, Mishnah Berurah 89:17 and 89:37 writes that making the brachos beforehand is preferable.
- Shulchan Aruch 89:3, Aruch Hashulchan 89:22
- Ishei Yisrael 13:23 footnote 61; cf. Biur Halacha 70:5 s.v. Hayah and Mishnah Berurah 89:17, 89:37 regarding working during the half hour before Alos Hashacher
- Piskei Teshuvot 89:22, Ishei Yisrael 13:31
- Ishei Yisrael 13:31
- Ishei Yisrael 13:31, Piskei Teshuvot 89:22
- S”A 89:7, Mishna Brurah 89:36
- Piskei Teshuvot 89:24
- Ishei Yisrael 13:21
- Halacha Brurah (Rav Dovid Yosef) 89:36, Avnei Yishfeh (pg 90) in name of Rav Vosner, Peninei Halacha (pg 162), and Piskei Teshuvot 89:24 are lenient for someone who regularly shaves. However, Sh”t Or Letzion (vol 2 7:9) and Halichot Shlomo (Tefilla 2:8) quotes Rav Shlomo Zalman Auerbach are strict under all circumstances and compare shaving to haircutting. Similarly, Yalkut Yosef (Tefillah pg 99, Siman 89:32) is strict but adds that those who do so regularly have what to rely on.
- Ishei Yisrael 13:37
- Kitzur Shulchan Aruch of Rav Mordechai Eliyahu 12:2
- Mishna Brurah 232:11 writes that the laws of learning before Mincha are the same as those for Shacharit after Olot HaShachar.
- Shulchan Aruch 89:6 with Mishna Brurah regarding Shacharit
- Mishna Brurah 232:9
- Piskei Teshuvot 232:3
- Rabbeinu Manoach quoted by Kesef Mishnah on Rambam Hilchos Tefillah 6:4, Mishnah Berurah 89:19-20. However, Halichos Shlomo 2:11 footnote 50 points out that the formulation of the Shulchan Aruch and especially Shulchan Aruch Harav indicate that the prohibition applies solely to Shacharis. See also Siach Halachah 19:17
- Halichos Shelomo 2:11:16
- Piskei Teshuvot 232:3
- Ishei Yisreal 27:27
- Mishna Brurah 235:17
- Shaar HaTziyun 235:19
- Mishna Brurah 235:17 at the end
- Piskei Teshuvot 235:6
- Mishna Brurah 235:17
- Piskei Teshuvot 235:7