You'll need a large compressor, not just the typical 20 gallon variety most of us have. This is a 60 gallon, vertical compressor with typically a 5+ hp motor. Then you'll need a decent paint gun (possibly 2; one for primer and one for color) which again is an expense. Then there's the question of where you'll paint the car. Renting a paint booth is best, but can be expensive and hard to find. You can always seal up your garage or shoot out in the wetted down driveway, but you'll inevitably get dirt and moisture into the paint.
Before you start painting, it is a good idea to keep an eye on the weather for rain or snow. You don't want to start painting only to stop abruptly because of the weather.
Take off the chrome molding around both the windshield and rear window. You can pick up a special tool at your local Mustang shop or by mail order that removes these quickly without scratching paint. Of course your paint is probably not in great shape at the moment, so a large flat screw driver will also do the trick. For some classic cars it makes sense to even remove the windshield, but classic Mustangs have chrome molding that will help cover any slight overspray.
Gloss - These paints have a high sheen level and are usually used on woodwork.
So lets start with Warm and Cool. When thinking about Warm, think about a desert panorama of gold, brown and earth tones. When thinking about Cool think of colors in the artic such as gray, black, white or think of the deep blue sea such as deep blues, blue greens and turquoise. Everyone can wear just about any color, the difference is in the shade of the color. When thinking of clothing, makeup or accessories, visualize Cool as a color with a drop of silvery-blue. Visualize Warm as a color with a drop of gold. For example, if you put a drop of gold to a red sweater it becomes a Warm red, but if you put a drop of silvery blue it becomes a Cool red.
Step four: the key to a finished looking painting is to build it just like a house...and by that I mean layers. Paint it in the reverse order in which the eye sees it to make it three-dimensional. By this I mean paint what's farthest from the eye first, and build layer upon layer towards the eye. In other words, do the background first because it should be the farthest from the eye, then add the objects on top of that, and then add the shadows to complete the look. Ultimately it's common sense. If you paint a bowl of fruit, the bowl and fruit need to sit on top of that background, much as it would in real life.
Purchase paint pan liners 5 for about $5. Once your done simply throw the liner out saving your paint pan and also giving you the opportunity to change paint colors without having to clean and dry the pan.