I begin my setup as I would with any printed material. I laminate and cut. Then I attach the material to a blank file folder using glue dots. I like the floral ones because they are thin rectangles and hold well. This one if from Montessori Print Shop.
Here is another example of a folder work. The pieces are rather small. The velcro ensures that they are not knocked out of place while the pattern is being built. This is from Montessori for Everyone.
I use velcro liberally on toddler works. William frustrates easily so this ensures everything stays put. He also loves to hear the sound of the velcro ripping when he's finished. This is from 1+1+1=1.
Of course velcro doesn't work on all materials, nor is it constantly necessary. I got this Cat in the Hat visual discrimination work from Joyfully Weary. I could have put the hats in a folder and left space below each one. Instead I designed it as one large sheet. Elora has to place each match carefully to prevent disturbing the other matches.
The folder/velcro setup can be useful whenever two sets of material are used. For example, Elora found these opposites cards confusing at first. I marked one item in each pair with a star which made it much easier to complete. I also could have affixed one of each pair to a folder and left enough space for the corresponding card.
Hopefully that gives you an idea or two on how you can add some fun with velcro. It adds a great point of interest and prevents the frustrations of accidentally shifting completed work.