A couple other tips I've seen/read:

If you're just using a small patch, cut it with rounded corners. They'll be less likely to lift in flight and when cleaning.

If the tear is long enough where you think a small patch wouldn't work well, only cut the covering from the opening that the cut is in. In other words, cut to the closest frame member all around. This makes it easier when you're ironing on the patch as it'll have wood underneath the iron.