It is a mitzva to designate a fixed place for prayer. It is even a mitzva for a woman who only comes to the synagogue on Shabbat and festivals to choose a regular synagogue. If possible, she should have a fixed place in the synagogue (see Peninei Halakha: Prayer 3:2).
When one has several synagogues to choose from, she should choose one in accordance with the guidelines provided by the Sages. A beit midrash (study hall) is holier than a synagogue (SA 90:18). Similarly, a synagogue that offers more Torah classes is considered preferable to one with fewer classes. In addition, it is better to join the congregation that places greater emphasis on Torah study.
If there are two synagogues which offer an equal number of Torah classes, the one with a greater number of congregants is preferable, for “Be-rov am hadrat Melekh” (“In a multitude of people is a King’s glory”; MB 90:55). However, if it is difficult to hear the ĥazan clearly in the larger synagogue, it is better to choose a synagogue in which one can properly hear the ĥazan (MB 90:20). Therefore, as a general rule, it is best that synagogues be as big as possible, for this increases God’s glory. Still, there is a limit; more than a few hundred congregants makes it impossible to hear the ĥazan clearly.
If in one synagogue people regularly chatter during prayer and in another they do not, one should opt for the synagogue that shows more respect for prayer, for he will be able to concentrate better there (Sefer Ĥasidim §770).
Most importantly, the essence of prayer is kavana. Therefore, above all other rules established by the Sages, the place in which one personally concentrates better is the appropriate place to choose (see Radbaz 3:472).
Similarly, one should preferably pick a synagogue that uses the liturgical rite of her ancestors. However, if she knows for certain that she will have more kavana in a different synagogue, she should prefer that synagogue (see below, 24:5).
If a man prefers one synagogue and his wife prefers another, and each synagogue prays at a different time, the wife should follow her husband, for he is more regularly in the synagogue, since he is commanded to pray there. Moreover, in all matters concerning customs and halakhot, the wife follows her husband, as explained below (24:4).
With every step a woman takes in her walk to the synagogue, she is rewarded. Therefore, even if the preferred synagogue is farther away from her house, she should not be deterred by the effort of walking, for she is credited for each step. This matter was in fact taught to us by a woman, as we have learned (above, 20:2; Sota 22a).