As some of the answers already given have alluded to different countries and ethnicities have different practices/conventions.
In my experience the place you are most likely to find a wife's maiden name is on her marriage documents.
Many places, but not all, record the mother's maiden name on her children's vital records .
You can also look for clues in the surnames of witnesses to events involving the woman of interest as well as the surnames of the main participants of events she was a witness to - close family are often the witnesses of marriages, baptisms, etc.
Depending on the time and place you may also want to look at middle names - sometimes the mother's maiden name gets used as a 'middle name' for a child - Similarly a woman's maiden name may become used as her middle name after she is married.
As was already mentioned look for clues in the census records for other surnames in the same household - sometimes a sibling, in-law, or orphaned niece/nephew will give a clue. Similarly, a woman's will may mention siblings or other relatives as beneficiaries.