The distressing on the opposite knee already had a sashiko-style mend pattern on it so I decided to implement something similar to my patch.
"The Conscious Closet" by Elizabeth L. Cline is a great resource for practical sustainable fashion tips including simple mends if you're a beginner! Highly recommend!
At this point you can decide if you're going for a more visible mend or if you'd like the patch to match or blend with the denim you're repairing. You'll see that I opted for a darker blue patch, but used light blue thread so that the overall neutral "denim" blue feeling remained. White, black or red thread or floss would be a great option if you're going for more contrast!