I was dealing with a similar problem not long ago. I had a big order to make and no experience with custom patch makers, so I was a little worried. I ended up doing several things to minimize the risk.
The first thing you should do is find a manufacturer who’s experienced, qualified, and has a good reputation. Look for brands that aren’t afraid to go over their previous experience and showcase their work on their website, and who have gathered positive reviews from customers.
It’s also better to stick with patch providers who offer some type of refund guarantee if the patches aren’t to your liking. Some companies will even produce a sample you can review before going into full-scale production, which can help you get a better sense of what the final product will look like.
Finally, make sure you choose the right material for what you want. As this guide explains, varsity patches are usually made using chenille. Patches for military uniforms, on the other hand, are usually embroidered.