I've occasionally printed 4x5 negatives on 11x14 paper but I pretty much stick to 8x10 paper for both 4x5 and 35mm. They are generally mounted on 14x17 board. I guess I just like smaller prints. It's a personal thing and there are no rules. Some photographers print small, some print larger. And some print all sorts of sizes depending on the image because they find certain images work better at different sizes. Sometimes the limitations are in the negative and finding the largest size that works without grain or unsharpness becoming distracting. There are lots of potential variables and it is all subjective. No rules.