Memorizing formulas is a huge bummer, but if you have to have them memorizied I would recommend a few things. I'm a little late for your SAT II exam, but hopefully this will help for your AP Physics exam.
First, I would really try to understand the formulas and why they are what they are. There are some things like constants and squaring certain variables that might not be intuitive, but reasoning out why P and n are on opposite sides of the equation PV= nRT, for example, REALLY helped me. I was less likely to make a mistake on the exam and if I started getting confused or unsure about an equation, reasoning using direct and inverse relationships helped me feel more confident on my college physics exams.
Second, I did as many problems as I could. Not only did it help me with the material for the test, but the more problems I did, the less I had to rely on a formula sheet. It can suck to make yourself sit down and do problem after problem, but this is the most efficient way to do it, I think. You can kill two birds with one stone.
And when it comes down to it, just writing out or saying the formula a bunch of times can sometimes get you through, but it's probably not the most reliable solution.
I hope that helps! Good luck on your AP Physics exam! :)