When spraying your house, it is a good rule of thumb to spray in the direction of the grain of the material. So if you have siding that runs horizontal, you want to spray in a horizontal style. Also, when you go to spray, the gun should be approximately 12" from the material that you are spraying. Do not pull the handle to spray with your hand still. This will spray a lot of paint in one spot causing it to drip. So have your hand moving when you go to depress the handle. This will give you an even look to your paint.
A good interior paint job is often 50% preparation and 50% painting. Do not rush in preparing the surfaces in your eagerness to get at the brush or roller. If you do not prepare the surfaces properly, you'll be back with the paint brush or roller in a few months.
Cheaper then doing it yourself. Some would argue that if you're going to all the trouble to fully prep the car yourself, then why not just shoot the paint as well? Why get a shop involved? The answer is simply that you'll get a better job and for less money. Some would argue with this, but the fact is that if you've never sprayed a car before then your first car will have a steep, and expensive learning curve. Laying down an even, consistent coat of paint takes considerable practice. Also, paint and equipment is not cheap. You'll need to buy primer, color coat, clear coat, reducers & catalysts. None of these are inexpensive and you can easily spend as much in paint materials alone as the cheapest paint job at Maaco or similar shop.
When you have all the tools at hand, examine your exterior. You might find exterior painting problems, which could be any of the following: alligatoring, blistering, chalking, chalk run down, crackling, dirt pickup, efflorescence, fading, frosting, lapping, mildew, nail head rusting, paint incompatibility, peeling, poor alkali resistance, poor adhesion, poor gloss retention, surfacent leaching, staining, vinyl siding wrap, wax bleed, or wrinkling.
What emotions does it produce?
At a minimum you want to remove all the chrome from the car. Take off both front and rear bumpers. If your Mustang has bumperettes that are body color be sure to bring them along so they can get sprayed at the same time as the rest of the car. Remove all rocker, hood and trunk molding. Same for wheel well molding and all emblems. This would be a good time to order some new emblems and attachment hardware. Also spend some time cleaning up all the chrome with #0000 steel wool. Nothing looks worse on a fresh paint job then faded emblems and corroded, cloudy chrome.
Pick a brand you can trust Companies with their own high-street shops, such as Fired Earth and Farrow & Ball, and those that sell through the DIY giants are the most accessible. However, buying paint online is increasingly popular and can bring you a wider choice, especially if you live outside major towns and cities.