I am a car wash fiend. I hate having a dirty car...particularly a dirty black car (my last car...). It also does not help that the water is horrible here in Vegas. I wage war againt the horrid water here every time it is time to wash the car. None the less, here is my own do-it-yourself torture instruction manual:
1. Start with a filtered water device of some form. (Mr. Clean auto dry filtered unit works fine, however, I am lucky to get 3-4 washes before the filter is worthless) Use staight water for the wash, and the filtered water for the rinse. I use Meguiars NXG car wash soap. Whatever you do, do not use dish washing soap like DAWN. These will strip you WAX off. (not all dish soap will, but DAWN in particular will. Handy if you actually want to strip your wax, but not so fun otherwise)
2. Wash the vehicle in sections. Do not douse the vehicle from end to end. I start with the roof. Rinse and water blade toward the hood, or sides. (You don't need a torrent of water to rise, just a nice spray from the filtered Mr. Clean unit works peachy) Micro fiber dry the roof (Do not use cheap MF towels, they WILL scratch/swirl your finish). Move on to the hood, repeat, sides, repeat, etc.
3. RINSE YOUR MITT REGULARLY. Trapped particles will scratch your finish. If you vehicle is covered in dirt/mud, pre-wash it to get most of the crap off before you start applying that mitt you will use to clean to the finish. Sponges are evil. A large portion of those swirl marks are caused by either trapped particles in the mitt, particles/woven edges on your drying towels (also applies to cheap micro fiber towels), or using touch up polishes/gloss enhancers without getting the dust off your finished surface. (Not to mention swirling large gobs of mud/dirt/dust around if you did not both to pre-wash) Also, use a bucket with a grit filter in the botton, it will help you avoid picking up grit off the bottom of the bucket, AND, if the wash water gets grey/brown, run up a new bucket, your are temping fate with the suspended particles in that nasty water.
4. Be careful with the Water Blade if you use one. They are great, however, if you catch even a small peice of debris on the blade, it WILL leave a nice scratch on your finish.
5. Buff out any evident imperfections with some 3M 39009. Some like Scratch-X, but in my experience, it does not come close to how well the 3M product works. I have used both (and some others as well), and the 3M gets the job done. A small random-orbital buffer works great for this. By hand it will get painful after a very short period.
6. Wax and seal with your choice. I prefer Zaino ZFX/Z5 (or Z2 if you do not already have swirls, Z5 if you already have swirls), and Z6 Gloss enhancer. On my Silver Birch GMC Canyon I use Meguiars NXT wax, which is just peachy for that finish. Mothers, Meguiars and many others make some very decent 1 to 3 step finishes. Zaino will take you the better part of half a day to do the finish in 3 layers, but on my cars it provided the best and logest-lasting gloss finish of the products that I have tried.
7. Love your California Auto Duster. Dust off the daily road dust each day and you can have a great gloss finish for months, with only occasional Z6 for touch up. (This of course assumes no rain, driving through washed out streets, etc. lol) Again, be careful with your auto duster, drag only lighly along the surface and it will pick up the dust just fine. Do not use pressure. Also, shake it out once or twice per side of the vehicle. A small particle of debris can and will leave a nice scratch in your finish (yes, this has happened to me, love that 3M39009).
If this is all just too much, or you don't have the same obsessive/compulsive cleaning disorder, try a auto wash place with live attendants that know what they are doing. Finally, if you just want to quick wash, Meguiars NXG car wash is great by itself (remember clean mit and clean wash water with grit filter), followed by Meguiars NXG tech wax (only needs one coat and done)