Lay shirt out on a flat surface
Line clipboard up with the center of the collar or shirt
Fold in one side of shirt
Fold in the other side
Pull the bottom of shirt all the way up until it reaches the clipboard
Tuck in excess part of shirt in(make sure it's in before clipboard, not over.
Pull clipboard out
There you have it...
A stack of nicely folded t-shirts ^_^
- Clipboard(plastic Clipboards are easier)