I DON'T.
I'll number the files, but I dont number actual pages.
THIS. I made a comic(supposed graphic novel) in which originally it was to have 50 pages; I ended up splitting the story in half(to be able to print it in time for a con), but the ending was off, so I had to add a few pages to make it end on a cliffhanger(and set the 2nd book up). It was easy to add in bonus pages since I hadn't "set in stone" literally numbered pages.