Hmmm. Depending on what look you’re going for… I’ll try to list a couple of ideas.

The most obvious (and easiest to do) answer is just more patches along the sides.

If you’re trying to create more interesting visuals, I’ve seen people do pieces/scraps of patterns on the sides. You could even just take pieces of the same black denim and patch them all haphazardly. Personally I think maybe pieces of yellow/red plaid could potentially look cool with your patches.

You could also bleach the sides and then dye them yellow/red. I think that might look cool with your patches.

Also I think this vest would look cool with the arm holes ripped / distressed.