I loved this project the instant I pinned it on Pinterest. I made some, and then we had family in town, so we stocked up on bags and supplies for 9 people (including 2 middle schoolers who did their own bags and turned out great) and gathered around my craft table and all made these a few weeks ago.
Here are a couple good tutorials -
here and
here (this one gave me the courage to try colors)
Here's where I found some of the supplies for the adult bag:
Totes - 13.25"x13.25" (single @ Michael's) or a 3-pack at Wal-Mart or Michaels (it's cheaper at Wal-Mart, but if you have a coupon, it's cheaper at Michael's). JoAnns has some, but I didn't like the shapes/sizes and most all have colors on them.
Doily - 10" - the design I liked was at Michael's. They have some at JoAnns, but I didn't like the design as much
Then there's fabric paint, freezer paper, a brush and spray adhesive, but those should all be easier to find. My spray adhesive is permanent and temporary - to make it temporary, you have to spray the doily and let it sit for 3-5 minutes before adhering it to the bag.
I found smaller bags at Michael's (only found one random pack floating around on the wrong shelf and couldn't find a spot for them, so I'm not sure if every store has them). Anyway, this size is perfect for toddlers. We were going to the birthday party for a 4 year old and after making the bag with her initial, I used it as the gift bag and wrapped the rest of her present in it.