Hey Rob, I like to use acrylic paint. I often use the store brand or equivalent. For me the benefits are that it is cheap, readily available ( no hobby stores close to me), semi transparent, water mixing and clean up, easy to control paint consistency. There are differences to spraying and brushing. spraying typically requires higher pressures, thinner paint and coats also a different nozzle on airbrush. This is the method I prefer, I realize that other people prefer other methods. I like to experiment with new methods and this is a cheap way to learn alot. That being said, I typically make up a color chart on a piece of copy paper with varying shades ( with the color green this could be different amounts of yellow or white for example) let this dry for at least an hour so you can get a better feel for the color. Then I compare the "color chips" to photographs ( keep in mind color variation, and wear as well as light difference and reflection) then apply.Also once you have the color on the vehicle and let dry, if you feel that it needs to change,apply another shade. This also helps to break up the monotone and give the paint job "life". Use PRIMER as first step. Experiment until you are happy. This is just a method I use. - Bobby