I made a small crossbody out of two old t-shirts and a leather strap that had fallen off of another bag. It's very simple to make the yarn and crochet, it just takes a bit of time.
Step 1: Step 1: Find a T-shirt
Use a t-shirt that is 98% or 100% cotton. I realized halfway through that I would need two t-shirts to finish off the bag, and I used all of the fabric, so try to get bigger shirts if you want a bigger bag! It's hard to get it all one color unless you have many of the same color.
I used one large men's t-shirt and one medium women's one. They can have marking or printing on them, as long as there isn't so much printing that it is inflexible. It's better to have ones without seams down the sides, but I used one with seams.
Step 2: Step 2: Test It
I started cutting a strip and tested it with the hook I would use to see if I liked the thickness and size. I cut it about 0.9" thick and used a 6.5mm hook, but you can vary it based on how you want it to look.
Step 3: Step 3: Make the Yarn
I cut the pink one in circles in order to avoid the seams. For the blue one, I cut it across, leaving an inch on the ends. Then, I cut the uncut inch diagonally to make one continuous strand.
Either method works out fine. It all depends on whether or not you want to avoid the seams! The blue shirt also had seams, but I decided to use them which are visible in the bag, but it doesn't bother me, and I got a bit more yarn out of the fabric.
Try to keep it the same width all the way through, but it by no means needs to be perfect, and the variation makes it look more homemade.
Step 4: Step 4: Construct the Flap
Crochet a semicircle to the width that you want your bag to be. I did a single crochet stitch. You can follow this pattern and add or decrease to create the size you want. I measured mine to fit my kindle.
Step 5: Step 4: Construct the Body
I followed this pattern for the bottom using the blue yarn except I used single crochet instead of double and only did 5 stitches across for the part in between the red lines. After the oval, just single crochet in round upwards. After two or three rows of that, switch back to the pink yarn. Continue until it is tall enough for your needs.
Step 6: Step 5: Make the Strap
I tried to do a macrame strap, but I ran out of fabric. You can also do a braided strap. In the end, I used a leather strap from a bag I was going to throw away.
Step 7: Step 6: Model Your Bag
That's it! You have a bag! Congrats! :)
Check it out on my blog.