i have a different opinion. posing nude would not increase your practice time. it would lessen it. for me, practicing a lot before a performance helps ease my jitters. i can't say i'm completely over them, but i've found a few things that help me. one is potassium. i like to eat bananas before a recital. and calcium (milk) because it helps me relax. i used to make milkshakes almost everyday (you know those power shakes). then as i became older, the milk just didn't go over so well, so i put a little milk, a lot of water, and a banana. it still worked.
everyone tells you to imagine something different. like the AUDIENCe in their underwear. that never worked for me. or, imagining playing for your family. that didn't work either (probably because they ignore me). just recently i have found that if i imagine playing my piece in front of the composer of whatever piece it is, (and read about them and absorb what was happening at the time they wrote it), i feel a sort of calmness come over me. i'm not playing only for the audience, but for as true of an interpretation as i can muster. then i become "into" the piece.
something else that is personal to me, is that i don't like to wait around. the more i wait, the more nervous i get. so, when i go on stage, i don't sit too long before putting my fingers on the keys and just getting started. i try to set the tempo and idea of the first couple of bars in my head, and then start accordingly.
speaking of the posing, don't you think it cheapens your self worth? i say, get married, let your husband/wife paint you all they want. marrying artisitic people can be a real zinger (with lots of ups and downs - and carrying on) but it IS true love. my husband is a singer (baritone). i have never painted him or visa-versa, but i did give him a calendar of myself (i bought twelve bikinis on sale one january) for every month. (right after a pregnancy, too, so i had a pretty good bosom). save the specialness of your body for someone who truly appreciates it.