I think that your question is interesting, but too broad for this forum. You have already pointed out grammatical differences in the past tense: Я сказал vs. Я сказала. Beyond that, I am sure there are differences in intonation, vocabulary, and probably many other factors.
I have recently listened to an audio course called He Said/She Said: Women, Men and Language by Deborah Tannen. Naturally, her research mainly involves English speakers. She points out that women speaking English tend to use rising intonation more often then men, making their statements sound a bit like questions. She also talks about how men tend to talk to convey information, while women tend to use conversation to maintain relationships.
As I have said, this is all pertaining to the speakers of English, but this might be a starting point for you, if you wish to look for similar research concerning the speakers of Russian.