I started with a black denim biker vest that I got from Depop.
Here's a picture of the finished vest.

First, I painted my patches and sewed them on.
Then, I put saftey pins on it. I also put spikes on the shoulders. They look better when worn, as they look like they are in the wrong spot when on a hanger.
I then put buttons on it.
Finally, I sewed on the back patch