Really, I usually do one page and stop. Still, often times I like a kit so much, or I have a lot of pictures that I bought the kit for, so I keep going.
I always MEAN to do more, but then I see another kit I like, or I get another assignment.....and then another.......
One thing I don't do is mix kits. Too much trouble. I'm sooo lazy. EVERY once in a while I'll pull one special element from another kit, but that is rare.