I use a clean (never used) Pizza box. It allows you to lay your blocks flat in it and when the lid is up...I use that for a mini design wall. When the top is closed it is my mini desk top to work on. Since it is just a Pizza box, I add a loop of elastic through the cardboard and a button(big hole to put elastic through) for a closure. I just push the elastic through holes that I made and tied a big knot on the ends to keep them from pulling through. You can add other loops of elstic for whatever tools you want to fasten in.