The first thing I make sure I do is to park out of direct sunlight. This prevents premature drying which causes water spots on the car. It is also nicer to wash a car in the shade then in the blistering heat. It also will not be as enjoyable if you are dying in the sun while washing your car. Next I get one on the buckets, fill it with water and add the car wash soap (I add as much as the directions on the bottle say to use). I then take the second bucket and fill it with plain water. Before I start washing my car I like to spray it down with the hose first. This really serves no other purpose than to blast of all the dead bugs and to loosen the dirt. I cannot stand scrubbing bugs off, but you can just as easily start washing your car without spraying it down first.
The next step is washing! Put your rags (do not use a brush they will scratch your car, only use brushes on the tires) into your soap bucket and swish them around for a minute just to get all soap and water mixed together. Start washing your car section by section starting with the top. When you need to rinse of your wash rag use the plain water bucket, you do not want to use the soapy water bucket. If you do, you will then be washing your car with dirty water. That does not make much sense when trying to get your car clean. When you are done washing a section rinse it off with the hose. You do not want the soap to dry on the paint and stain it. After you rinse off that section move on to the next section and keep this