I had about 450 hrs civ before I went in, no multi time. I went through Vance about 14 years ago, so here goes:
One of the best things for me at UPT was making friends with a guy who was about 4 months ahead of me in the pipeline. He gave me an excellent heads up as to what to expect. Mind you, the present will always be what counts, so don't try to study ahead, but he was a great help when it came to helping me learn flows in the Tweet and things like that. These concepts were foreign to me as a civilian, where you learn to "read and do" on the checklist. Also, we'd get together and "fly" formation in the parking lot with each other. Sounds stupid, but it sure gave me an idea what to expect when I got in the air. The formation phases were the most fun, I thought, probably because of him.
In 38's, nothing will prepare you other than finding an airplane beforehand in which you can fly instrument approaches at 300 kts, and practice landings at 150-190 kts. The only guy we lost in 38's was early on, because he just couldn't get the landings down. Every one of the other 10 (out of 22) we lost was in Tweets.
In both phases, know your Ops Limits/bold face early. Make flashcards. Be humble and honest with yourself and your IP's about your shortcomings but always make sure they know you're motivated to improve. Be disciplined with your time off, but do remember to give yourself time to relax and get your mind off things occasionally. There is time to have fun, just know when it is. Remember, some guys will have to study more than others, so don't necessarily do what your buddy is doing.
Realize it can be a little political. The guys who get out and get some face time at the club and interacted well with the IP's seemed to do well in the program. The wallflowers, not so well. There may be a lesson there. On the other hand, the wallflowers may have been wallflowers because they were not great students and couldn't afford to spend time socializing, I don't know. The point is, give 120% while you're there, and get to the club when you can.
Oh, and don't date the Wing Commanders' daughter.
Over and out.