Most importantly I think is to draw numbers 1-90 on the sheets... I did that for practice tests. That way I could note for my self which question, and, more importantly, which answer choices I felt doubtful about... That way I could also cross out the ones that are for sure wrong, leave 2-3 choices and circle the question. When I return to the marked questions I don't need to read the choices that are for sure not right.
The second sheet I will leave for calculations in gen chem and notes.
Then before PAT I will quickly erase all answer choices for sciences and start PAT, going the same strategy of marking but using the second board for paper folding and cube counting.
The paper folding grid takes 5 seconds to draw... no point to draw it beforehand.
For RC and QR I don't usually pre-write anything, except for dividing the sheets in halves so that more words fit in (works with my handwriting).. I am using the keyword strategy there.
For QR I usually don't have enough time to recheck the answers =) But I think it might be beneficial to write numbers 1-50 on one laminated sheet and then use that for both RC and QR, while using the 2nd sheet for notes/calculations.