I had bought a few of these burlap peanut sacks at an antique store awhile back. I decided to turn one of them into a drawstring bag. Not sure what I'm going to put in it yet, but thought it turned out cute!
First, turn about an inch of the top of the bag inside out like the picture below.
Next, get a piece of twine long enough to wrap around the bag plus a little longer and put it under the flap you just made, all the way around the bag.
Sew (or use liquid stitch) the flap down on each side of the bag. Sew right above the bottom of the flap, where my finger is pointing in the picture below. Be sure you don't sew the twine to the bag!
Once both sides are sewn, tie the two ends of your twine together and you're done!
P.S - While in the clearance section at TJ Maxx the other day, I found this mason jar with a chalkboard label and hole in the lid, made for a straw. Turned out perfect for my twine and would be a super easy DIY project if you wanted to make one yourself!