I think if you go through the material enough times you will remember the formulas and tidbits almost effortlessly. I didn't use my scratch paper to write any tidbits/formulas on paper. Just write them as necessary for example you could waste time writing fown rault's law and it may never come up on the actual test.
It's best just to write them as needed, you want to spend as much time reading and answering the exam as possible. I didn't write anything on my scratch paper I just went right into it.
I hate to be THAT guy, but this thread has been started about 1000 times. Look at the content list and know all of that for the test. Memorize/write it/understand it/whatever works for you.
Even better than formulas is to know units (ie what is a Newton). I didn't really memorize any formulas for physics and figured out quite a bit on the actual MCAT just by knowing what unit my final answer needed to be in and how to multiply numbers they gave me in the problem to get to that correct unit.