Having 3 kids sorta close together they went thru the preschool years together, then there were years where they were all in elementary together. Two of the three were quite artsy at that time and the third liked to be proud of his stuff too. They all wanted to display everything on the fridge where everyone could see it. Needless to say it always looked messy instead of displaying their hard work and artistic ability. We made a rule in the house that you were only allowed one picture each on the fridge. If you made something new and you wanted it there you had to remove the old one. You could keep any pic up as long as you wanted but only one was allowed up. Then they had a choice from there. It could go up in their rooms, go in their "keeper box" or put in the garbage. I always left that up to them.
It worked great for us. You could actually see their nice artwork and it taught them to make decisions about what they really thought was worthwhile to keep.