My wife & I like to go rock climbing. She needed a good bag to carry her harness, chalk bag, etc. This bag was an interesting challenge. I wanted to crochet it (I don't know how to knit), but crochet stretches pretty easily. If the bag was going to hold anything of any significant weight, it would need some support. I purchased a woven nylon strap and sewed it into the base of the bag and around my wife's shoulder. I then crocheted around the strap to make it match. To give the bag a nice interior, I sewed in a lining. I also purchased extra strong magnets to secure the flap of the bag so it wasn't just loose.
Overall, the bag came out really nice and very sturdy.
See more below:
The strap incased in crochet:
