Check out my other instructable similar to this : http://www.instructables.com/id/T-Shirt-Folding-Machine/
Step 1: What you need
A few long pieces of cardboard
Scissors/ Box Cutter
Big Tape/ Duct Tape
A Tape Measure
Step 2: Measuring and cutting the pieces
2 pieces of 11 inches by 13 inches these are pieces A
1 piece 44 inches by 13 inches this is piece B
1 piece 22 inches by 13 inches this is piece C
Using the marker, trace the dimensions and cut them out
Step 3: Assembly
Both A pieces are to the left of piece B, and C is to the left of B and below A.
Once they are laid out, tape both A piece together. Tape the bottom A piece to the top of the C piece. Then tape the top left side of B to the top A piece. Make sure not to tape any other areas.
It sounds confusing, but the pictures really help