It's kind of time consuming to pick through everything, but I buy most of my patches from sellers on etsy, there's a pretty good variety and people can leave reviews so you know whether someone is legitimate or not. Either that or I just search for designs I like and cut stencils with an X-acto - old fabric and acrylic paint (this shit never comes out of anything, and if you're really worried about it cracking from washing/drying you can mix it with textile medium) will suffice.