Many of us hobbyists are "past their prime". I usually tell ladies who have not seen me that I am 50+ years old and no Brad Pitt or Tom Cruise but I am no Shrek either. I tell them I still have most of my own teeth and some of my hair. I also say I do not have a hair loss problem, but simply a hair distribution problem. Poking fun at yourself and making her laugh is a great ice breaker.
Keep things simple here, treat a lady the way she deserves to be treated, make her feel appreciated and wanted and make her laugh. The true professional ladies here mostly care about being safe and not being taken advantage of (like some guys who will try a "slip-N-slide" on them or others who try to "short" the donation).
Ladies here are used to guys not being in their prime anymore....hell, if we were, would we be here or out getting it for free?