You scuff up existing paint for two reasons. First, you want to get rid of any oil, grease or dirt trapped in the top layer of paint. This is the stuff that cleaners and degreasers can't get off. The second reason to scuff is to set up a physical bond for the new primer and paint to adhere to. You want to give the old paint some tooth so the new sticks better.
The paints may be applied by brush or spray; the small spray attachment for vacuum cleaners is very convenient, especially for painting radiators.
One precaution: You can't paint with it in cold weather. The chemical reaction that transforms the water solution into a durable finish will not take place if the temperature is below 50°. (Conventional oil paints don't stick well in cold weather, either.)
To personalize your colors is to know your Season. We use the Seasons as a way to describe which colors look best on you based on eye and hair color and skin tone. To determine your Season, Color Me Beautiful moves you through a two-step process. First, you will learn Warm and Cool. Second, you learn whether you are Light or Deep. Once you have completed these two steps you are there.
Gloss - These paints have a high sheen level and are usually used on woodwork.
Use Plain White Primer for Light Paint Colors. In our first case, if you decide to paint a wall in your house with a light yellow color, but the wall is currently a deep dark brown, you will go through bucket after bucket of paint trying to cover that brown, easily doing 4 - 6 coats or more. But if you put down a coat of white primer first, you could be done after 2 coats of paint.
The reality is that the guys shooting paint, even at the cheapest shops, know how to do it. They spray a dozen cars a week and have plenty of practice laying down smooth, consistent coats of paint. They work quickly and efficiently because they have to or they don't make money. They don't really make their money on shooting paint. They profit from body work because it takes time and insurance work because it pays well.