The most reliable, low-effort strategy is a tiered defense system that combines tall or deep fences for high-value plants with tough plants the animals hate. You choose fencing for your vegetable gardens or fruit trees because it is the only way to completely stop them, requiring an 8-foot height for deer or a 3-foot height buried 6 inches deep to stop rabbits from digging.
Then, you choose plants that animals naturally dislike for the main open areas of your yard as your easiest base, filling the landscape with heavy scented, fuzzy, or leathery plants that deer and rabbits hate the taste and texture of.
Finally, you use spray-on deterrents only for short-term protection on a few favorite flowers right as they start to open, which saves you from the exhausting chore of spraying your entire property after every rainstorm.
By putting a buried wire fence around your food crops, filling your main yard with tough plants like lavender or lamb's ear, and saving the sprays just for your prettiest spring flowers, you get total protection with very little weekend chore time.