Not sure how much you've done with girls - any suggestions, for things girls could try during sex to make it more awesome for guys?

next to zero experience there. and to address the usual cliche, from what I know it can take a fair bit of convincing to get a straight guy to let you stick a finger up his ass, nevermind you yourself knowing what do do once you're in there; otherwise it's about as "intimate" as a medical exam. and for all that, he may discover he's amongst the part of the male population that just doesn't get much enjoyment from prostate stim, or may actively dislike it.

but no matter who you are and who you're with, you need to remember the mind is as important as any other body part as far as having awesome sex goes, and possibly the trickiest to stimulate properly, but as the saying goes.. get the mind going and the rest will follow.

Have at it.