If you were hoping I'd say something rude, sorry. However, in the interests of saving time, there are a few things that I do whilst I'm in the shower to make sure they get done and because if I don't do them in the shower often I don't do them at all.
Lip scrub - I'm using a Morgan Annie one at the moment. It's latte flavoured so smells and tastes amazing. As an added bonus it keeps my lips soft and smooth (as you would expect from a lip scrub).
Face mask - I very rarely use face masks out of the shower. I have good intentions but it never happens. When I get the time to relax the last thing I want to do is put on a face mask, I usually want to sleep, which is why doing my face mask in the shower is such a great idea.
Hair treatment - You know how most hair treatments say to leave them on for 15 minutes? I never do that. I put the hair mask on, shave my legs and pitts, wash my face then take it off again. No more than five minutes. Gone are the days when I have the time to spend 15 minutes or more with a hair mask on. If my hair is in dire need of deep conditioning I'll put a mask on and leave it overnight, then wash it out in the morning. If you are going to try that, make sure to put a hand towel over your pillow so it doesn't get all greasy.
Intense body scrub - Before I start the shower I'll scrub my whole body then turn on the shower and wash it all off. Using a scub on dry skin intensifies the effect, so if you have sensitive skin it's probably best to add a little bit of water.
Moisturising - When I'm in a real hurry I'll apply a body oil whilst I'm in the shower (after I've used a body wash), lightly rinse it off and then pat myself dry. Doing this means that I don't have to put on body lotion after I get out of the shower.