I have noticed that a lot of people don't read profiles before setting up a language exchange. I have a rule on exchanges myself (a time constraint). I now have a warning in my profile and if they don't mention they understand that rule in their first email, I usually don't respond to them.
You can have any rule you feel comfortable with. It may be old fashioned but I will add "especially as a woman".
I'm surprised to read that.
I used to have the same problem, but not having a real profile picture has helped a lot (even though I feel a little uncomfortable hiding my face).
I'm sad to inform that people don't read profile descriptions (check mine, it's pure gibberish!)
You can choose not be shown at the language exchange listing in your configurations. Most people say it helps
Earlier on receiving a request I poped in respondent's profile to check out the exchange possibility, and then zealously explained why I could not be helpfull. Then I considered this to be tedious, and currently I add everybody who has fulled profile and userpic without any respect to exchange. Sometime they write somthing, like the "How is it going, and what do you plan for today", I answer. But not more! It's seldom they return to the conversation next day.
But I have three my requests hanging to people, whose accounts directly state that the owner seeks for Russian-English exchaged.