I tend to use my Durst Commask, a 8x10 easel with set size borders of about 1cm. You can also flip it over and print either 2 5x8's (less the 1cm border) or 4 4x5 (less 1cm borders between images) on one 8x10 peice of paper although I mostly print at 8x10 size. I use this easel mostly due to the simplicity of it (open, insert paper, shut... always get same border) and it's almost identical thickness (height off the baseboard) as my test strip device (Paterson I think) so although I refocus after doing a test strip, the image size is almost identical and no exposure alterations need to be made.(posted 8550 days ago)When printing larger, I'll use a 12x16 sheet (as large as I print at the moment) and put the image in the middle at whatever size I decide to print at.
Also, I guess it depends on who (and how) you show your work too. No one see's mine unless it's in a display book I use or been matted so they don't get a chance to put their grubby fingers all over them!