I am always a little nervous about putting out boxed puzzles for free access with a group of my buddies. They never seemed to get used in the manner they should and pieces often go missing. In a busy room, it's sometimes hard to supervise the puzzle makers as well as I should. I found an easy way to make the puzzles more interesting and the pieces easier to keep track of. Magnetic tape to the rescue!
I put some on each piece of puzzle. - Now, my buddies could use the puzzle on a cookie sheet, or I could put it on my fridge where it is easier to keep an eye on!