The main reason I make my own prints is for the record-keeping, so a 6x9 print size on 8x10 FB paper works perfectly fine. But when I do exhibits, I go up to 11x14 and 16x20 sizes.
I print 5x7 and 8x10.
5x7 is only for portraits of family and friends.
I use only 35mm film now.
In the past I used 120 film (6x6 to 6x9) and printed upto 11x14, but oneday I thought 35mm film and max 8x10 combination is enough for amateur like myself. It is easier to concentrate.
I have no chance to exhibit my photos, but if I do I think I can do with 8x10.
I feel that different photos look good in different sizes. one may only look good in 5x7 or another in 20x24. I look at the photo and feel I like to see it in a certain size. and sometime after printing it may look better smaller after I print it large. Just depends
mike