If your t-shirt, already has a pocket, remove it with a seam ripper. If not, measure where you want your pocket to go.
Step 2
Cut out your pocket using the original pocket as a guide. If you're using a t-shirt as your fabric, use the hem of the t-shirt as the top of the pocket, as seen below.
I made mine about 1/2 an inch larger on each side since the original pocket was really small.
Step 3
Iron down the sides of the pocket, and then carefully pin it to the shirt. Sew around the sides of the pocket with a straight stitch and then press.
Step 4
Sew around the sides of the pocket with a straight stitch and then press. And you're done!