T-Shirt Bag
With just a few easy steps you can turn any T-shirt into a handy little bag. Stick it in your purse for an extra little shopping tote. Use it for the gym, the library, or the beach. You'll be sure to find many uses for this lightweight bag. It would also make a great gift. Customize it for the person your giving it to. For Example a school logo, a concert tee, a favorite brand, etc. 
Step 1: Lay flat a clean, ironed T-shirt (this one is a women's size L)
Step 2: Cut off sleeves just inside seem line.
Step 3: Using a large bowl as a guide, trace out neck with a waterproof marker or chalk.
Step 4: Cut out on marked line.
You could then inside out and sew seem at bottom. This is how all the instructions I found said to do it, however I thought it looked too much like a tank top.
So instead I turned the shirt so that the side seems were centered.
I then trimmed the neck of the tee to look more rounded. You just need it big enough to fit your arm through.
Step 5: Hem around arm and neck holes. This gives it a more finished look.
Step 6: Inside out and Sew right above seem line on the bottom edge of tee.
Then throw it over your shoulder and your ready to go!