I got this idea from a site a long time ago but dont remember the name I thought it would be good to post it here so this is really a version.
Get a slightly fitted T-shirt.
Flip T-shirt inside out and with your chalk or fabric pencil draw your pattern.
Cut out pattern carefully I did not do so good on this part I have shaky hands. :S
You're done. Wear and enjoy that was quick and easy.