The symmetry trick is the one Kaplan uses...but it is only good for simple folding patterns. Anytime the paper isn't folded symmetrically, there is a chance that you will lose symmetry...that doesn't mean every asymetric fold will wind up with assymmetric holes, but it could.
I draw a giant 4 x 4 square on a whol sheet of paper. I then start with the back fold and work backwards and make dots wherever I believe a hole will appear. Sometimes with more complex forms you have to erase holes as you work your way backward, and other times you don't...but this is a fairly easy way to work. After your done with the problem, erase your holes and start again (thus the giant size cause it makes erasing small little marks easy.)
it'll take time to learn to do it fast, so practice. I've always gotten 100% on the hole punch section since I've started using this method...even with all the stupid DAT achiever 1/8 folds and other weird things. I hope that isn't on the real DAT, but we'll see...I take it tomorrow