One of the most difficult things doing a lot of craft and art stuff with the minimads is how to display it and then store it or recycle it.
We wanted to have some on display in our kitchen and after using blue tac and it leaving marks on the walls decided to hand some tension wire (the type for hanging net curtains or shower curtains) and hang the pictures on that. It works a treat.
Once they wires are getting full I take a digital picture of the boys work and store the best in a concertina file (i have one for each of them) and recycle the rest.
They also have a magnetic strip from Ikea on their walls in the bedrooms and they put their favorite ones up there too.
I have just ordered one of these mega pocket hangers each to hang on the back of their bedroom doors to hold some of the photographs of the artwork we take.