I spray some degreaser (Simple Green or whatever I find at Home Depot when I run out) onto a rag, scrub the chain, scrub the cassette and chainrings to get the worst gunk off. Dry it, put on lube (I've been partial to ProLink for years now, but I can't say it works any better than anything else), wipe, done.
Takes maybe 10 minutes. Usually do it once a week or so (which for me is about every 150, 200 miles).
Seems to work. My chain is quiet, it shifts well, I get decent chain life.