recipe for plastic bag bag

Cut bags around and around into long strips. The width of the strip depends on the thickness of the plastic. Grocery bag strips are about 1 1/2 inches wide. Cut thicker plastic bags 1/2 inch or so wide. I use a 4 mm crochet hook. Some bags are hard to work with (sticky plastic). If you find it really hard to pull the stitches through, discard the stuff, as it's hard to make stitches look even, and it's too much work to be worth it (unless it's a fabulous colour or something). A technical thing - one bag's worth is about one round, so you have to join strips. What works well for me, is: When you get almost to the end of a strip (maybe 4-5 inches left), do the first half of a stitch (pull up a loop, two loops on hook), then complete the stitch with the beginning of the next strip . Tie the strips together with a single knot, and crochet over the ends as you go along. This becomes quite easy and automatic after awhile. It's neater than trying to tie all the strips together beforehand. I cut a lot of bags and roll the strips into balls of matching types, so colours can be added when you want them.
For a tote bag:
A large bag is 40-44 stitches in length, a medium bag about 32. These take from 50 - 70 bags, I think. (I haven't counted).
Crochet a chain the size you want +1 for turning. It helps to know the number of stitches, so your base piece is consistent, and so when the ends are joined they have the same number of stitches.
Single crochet back and forth, using a chain 1 turn at each end. I found that a double bottom is useful for stability, so make your piece twice as long as you want the width of the bag to be.
Fold the bottom piece in half and single crochet around the edge, joining the two halves together (through the stitches on the last row and through the loop on the starting chain), going through both edges, and crocheting along the fold. When you reach the starting point, then just go around and around, working with the outside of the bag toward you. In order to shape the bag a bit, it's necessary to do some decreasing, as the bags tend to flatten, and so would be wider at the top than at the bottom. So decrease 1 stitch (insert hook, pull up loop, insert hook in next stitch pull up loop, then pull through all three loops on the hook at each corner- 4 stitches decreased per row) about every 6-8 rows or so (whenever you think of it) . When the width when you flatten the bag is the same at the top as the base dimension, stop decreasing. Or if it's getting tall and is still too wide, decrease more often.
When the bag is as tall as you want, it's time to make the handles. Going around the handles with a reverse crochet is both decorative and makes the handles not so stretchy, so the handles need to be only three stitches across (they seem too narrow, but you are going to add two rows afterward).
Crochet 12 stitches in from the edge (for large bag) 11 for the medium one. Chain 1, reverse, single crochet 3 stitches, chain 1 reverse work sc 3 for 46-56 rows, depending on how long you want the handles to be. Handles are on each side of the bag, not across the opening. Place the handle 12 (11) stitches in from the opposite edge, making sure that the working loop is toward the center. With right sides together, slip stitch or single crochet the handle to the bag, working through both stitches. Don't worry if it looks a little bit crooked. Then continue around the bag for 21 (19) stitches and repeat the process for the second handle. To place the second handle, flatten the bag and match it to the first one (or count stitches). Fasten off when you've joined the second handle.
Then, find some plastic bags that are crinkly (Walmart bags or others that are papery, not sticky). Join the strip to the edge and do reverse crochet around the handles and the top edge. Which means, go left to right around the edge, rather than right to left. Put one stitch in between each row on the handle, and maybe no stitch at the very base of the handles. When you get to where you started, fasten off, and cut the strip about two inches long. Work this in on the wrong side. That's it.
These bags are worked on the outside. If you want to add beads or buttons, you have to work with the wrong side (inside) facing you. String the beads or buttons on the plastic, and when you want to place one, pull up a loop, slide the bead or button in place (on the right side) and then complete the stitch.