1. Gather
supplies of any kind of playing cards or business cards. Make sure
that your parents will not be missing their poker cards for the
game on Friday night, or that you don't take that new box of business
cards in your mom's drawer.
That is all that
you need.
2. Figure out a way to build with the cards without using glue or tape or other adhesive materials such as cement or mud.
3. See if you can build a tall building and what shape allows the greatest strength. Build it TALL!
4. With business cards, you can build incredible cube based structures. Six cards folded into one another to make a six-sided cube. Make multiple cubes and you could be constructing like this...
Approach any business for leftover business cards, you will surely get tons donated.