West LA/Malibu, South Jersey, Charleston SC and Rincon PR are a few of the Surfrider Chapters that are making reusable bags at chapter meetings, film screenings and community events. Many Surfrider Chapters have used this step-by-step guide from instructables.com to make T-shirts into Reusable Bags with a sewing machine. (Check out the comments on their guide for additional tips)
Here is a tutorial for a NO-SEW option from savvysugar.com to turn a t-shirt into a reusable bag that the South Jersey Chapter has done at tabling events. “It is very easy and the bag is strong but it does take a little time. We use my pinking shears, I like the look of that and it keeps the material from fraying, and we usually cut the neckline to make the opening bigger, easier loading and emptying that way!”
TIP: if you use unprinted t-shirts or turn them inside-out you can take the additional step of screenprinting them with your logo and/or message! Here's one guide I found after a quick search.
What else have you done to make reusable bags? Let us know in the comments.