All of my cheatsheets (really, they're worksheets) are in "landscape". I've said this many time, but shall repeat:
Each worksheet is specific to the shop I'm doing. Each shop I perform has its own worksheet that I fill out. Among the areas to be filled out on each one is the specific address and MSC identifier (like visit ID, etc) as well as the date of the shop and pertinent areas and photos needed or required.
After each shop is performed, I staple any receipts or other pertinent items that I've received in the course of performing that shop. For instance, when doing a bank shop, I would staple the business card of the banker to the worksheet. Booklets and other information are filed away with shop's identifier written on them.
My worksheets for each month are filed away in a folder of that month in which they were performed. It really does not matter to me whether the MSC is different, it is the month that matters.
I could go on.
BTW, about those "Reward Certificates": I'm assuming you refer to the "Yellow" gas stations. I used to print out each Email regarding them. After much waste of paper, I too went to printing out a few reward certs with the Ticket number left blank. On my worksheet for the "Yellow" shops I fill out a space titled "ticket number". If i do 3 "yellow" shops for the day, I'll be certain to have 3 reward certificates with me. If, indeed, i get to present one per the guidelines, I just write in the reward ticket number. saves my time and a lot of paper as it is seldom that I give those out!