Collect materials. Find a flat piece of trash (FPT), styrofoam or cardboard works well. Then obtain scissors or a knife that will be able to cut through the trash.

Cut a side of the FPT that will be one side of a square. Use the cut piece to measure the other sides of the square.

Cut all the sides until...

you have a completed square.

Cut the two opposite corners diagonally.

Then cut across.

Put one of the triangles aside, and cut the other triangle in half to form two smaller triangles.

This is what you should have so far.

Set aside the two small triangles. Fold the big triangle as shown. If you cannot fold the FPT just estimate and skip to step 10.

Cut the big triangle as shown.

Cut the big triangle again to form the three pieces shown.

Pick up the piece to the right and cut as shown, forming a square and an even smaller triangle.

Pick up the piece to the left and cut as shown, forming a parallelogram and a triangle.

Putting back together and....you made a tangram puzzle!

Here is just one of the many possible images you can make.