I have my own methods, I detail my own vehicles and maintain them as well. A good tip I can give is to do a very thorough deep clean on your car, and then maintain for every day you drive. This may sound like a lot, but it really is not:
Once you get your vehicle clean (especially interior) minimal time is needed afterwards if you do quick daily upkeep. I shake and brush out my floor mats daily, takes about one minute. Stains? Buy a $4 can of Tuff Stuff at Walmart, it's a foaming cleaner that will lift almost any stain or tough dirt in a minute, and goes a long way.
Glass: Fingerprints, waterspots, etc. Just keep some microfiber towels around and wipe the interior glass with them, using NO cleaner. Microfiber towels are great for cleaning glass quick in this manner.
Windshield: Find a gas station you like that uses real detergent that you like, instead of water, and do a quick scrub with the squeegee. Free, and very effective while you are filling up.
Tires: Ironically, the best touch-up I have found is Turtle Wax's foaming cleaner and shine, and their black and wet spray as well. Ironically, it works FAST, lasts longer than Armor-all or other brands, and is also the cheapeast.
If you run 20-30+ trips per day like I do, it pays off to do minimal upkeep daily. I have several 5-star comments on how clean my car is, and it pays for itself. Total time for doing daily upkeep is minimal, maybe 15 minutes, maybe a $1.50 per day in total products used. Tips cover the cost of this and most of my gas, and I drive a V8.
If you constantly keep up on it with touch-up maintenance, it's minimal and you can go a long way with it.