Be explicit in what you want in your subject line and the first paragraph of your profile (since this is all that standard members can see) otherwise you'll attract the wrong type. Don't go for a newbie unless you think you can groom him toward being a bull, which you probably can't if you don't have any experience.
A lot of single guys on AFF aren't, which is revealed when they can't host for some ridiculously made up reason. Single guys who're past college age tend to get attached unless they identify as bulls. Sometimes even bulls get a bit bitter when they're discarded. Married guys have hard time finding time.
If I can think of anything else I'll post it.