Nate,
You are doing about all you can do if you are pre-rinse. Rinsing right after the chem app, and post rinsing. Adjusting your mix to a weaker strength may help ( and still work on the resi) but simply may take a little longer dwell time.
Constant rinsing of the plants and lanscape is the key. Most species of plants will not mind all the extra attention.
Some may say to cover the plants with painters plastic, which IMO, seems to serve better in the Winter vs. Summer months because they can be burned up within minutes.
Rinsing is the key. If you do not see an instant injury to the foliage from your mix overspray, then you are ok in most cases. If you have a helper, he should or can be rinsing during the entire process and well as serving as a swamper and hoseman for you while you are cleaning.
just my.02