In general, the more forth coming about your expectations, the more targeted your inquiries will be. For example, if looking for AI, clearly state it in the title or body copy that there is to be no sexual contact. If you're wanting an anonymous donor, it's good to state that as well.

If sharing a photo in a private message, choose one that shows a good side of you. A bad photo is worse than none.

Respect each other's choices. If you reach an impasse that can't be resolved through timing, kindly let it be known and move on.

In my experience, taking the time to chat with your potential donor/recipient and get to know them as a person fairs way better than approaching someone with just a word or two. Creating life is a connection that lasts from now into the future, whether you want to maintain anonymity or not. Building a good rapport will help ensure mutual trust and understanding, and make the process that much smoother.