First you are going to want two t-shirts, pick decent sized ones, because the shirts will get smaller as you go. Make sure your shirts are bigger than the size purse you want.
Then you are going to chop one shirt. I was planning on doing two, but I'm glad I didn't. The front of the shirt will be the front of the purse, and the back of the shirt will be the back of the purse. It helps if you cut them the same size, I cut them two different sizes, which made the task a lot harder than it needed to be.
Once you have cut these out...fold over the edges you want to tie, approximately 1 1/2 inches, if you want longer ties, fold them over for about 2 1/2 inches. I made the bottom on the shirt, the top of my purse so I didn't have to cut it or stitch it, since it was already done for me.
It's okay if you have an extra fold..you will just have to cut them so they are even later on.
Then you will measure your cuts one inch apart and cut on the fold. It helps if you do the sides first, then do the bottom.
I folded over too much, so I had to measure 1 1/2 inches, then cut.
Then, you can fold over the bottom...be sure you aren't folding over any of the cuts you already have. Make your length the same as the sides, if you did 1 1/2 inches, make the bottom 1 1/2 inches. Then measure your cuts 1 inch.
Then, you can start tying each side....be careful! Cut up t-shirts are very delicate and could rip easily. Your corners are going to be more delicate than your edges...so, pay attention.
When you are done, you will see that your purse has kind of taken on a mind of it's own, shrunk, and made it's own shape...it looks better when it's not laying down. If you don't feel confident, hold it up and see if you like it.
Carefully turn your purse inside out to see if there are major holes. Leave it like this if you choose to do lining. You will end up cutting another shirt to fit the shape.
If you choose to use lining...cut out another shirt. Make sure you cut it to about the size of the purse or perhaps a little smaller. It is up to you if you would like to sew it or stitch it. Check often to be sure the lining will work for the purse, this was my most difficult part, so I don't have a lot of pictures.
Also, you could make the lining removable by choosing not to attach it to the purse.
Then you could use whatever left over materials you have to make a strap for your purse. I had two long leftover materials from my shirt, tied them onto the purse and tied them together.
And...TADA! You're done!!