Basically what you're looking for is a good, solid foundation of existing paint that is stable and still strongly bonded to the car. Many times an original factory paint job, even after decades will meet these criteria.
Remove side view mirrors (unless they're to be body color) as well as exterior door handles and locks. This will take some extra time because you need to remove the interior door panels to get these off, but it's worth it. Head lights, tail lights, marker lights and license plates should come off too, but you'll need them in place to drive to the paint shop. So bring some tools so you can quickly take these off once you arrive. Depending on the year Mustang you can just take off the chrome bezels or rings. The shop can then easily mask the headlight or tail light itself and still get plenty of paint around the edges.
Valspar Paint, for instance, also produces paint branded as Laura Ashley, Eddie Bauer, Waverly, and more. These separate lines, or collections, have their own color wheel displays and are usually available wherever the primary brand, Valspar in this case, are sold. Other examples are Disney Paints, currently produced by Behr, and Ralph Lauren and Martha Stewart, formerly produced by Sherwin Williams.
Plaster. New dry plaster in good condition, which is to be finished with a paint other than water paint, should be given a coat of primer-sealer and allowed to dry thoroughly before being inspected for uniformity of appearance. Variations in gloss and color differences in the case of tinted primers indicate whether or not the whole surface has been completely sealed. If not, a second coat of primer-sealer should be applied. If only a few "suction spots" are apparent, a second coat over these areas may be sufficient.
When all of the spraying is complete, its time to remove all masking tape and paper and start touching up your entire home. This step is pretty time consuming because this is the final stage that really makes your home look good. The more time you spend here, the better your home will look.
Alkyd is an old interior paint made newly popular by a change in solvent - a super-refined petroleum chemical that has almost no odor. It is not a water paint. You thin it and clean brushes with mineral spirits or turpentine, or, if you want to retain the odorless feature, with the new odorless solvent. (Ask the paint-store man for just that, odorless solvent).
Once you figure out which position is prime and which position is spray, place the valve in the prime position and grab the primer hose. Point the primer hose in the empty bucket near the top and at an aproxx.45 degree angle from the side (the reason for this is that there is likely to be pressure still built up in the airless and when you first switch on the airless to prime it, paint will likely burst out of the primer hose and you don't want to have it go everywhere). Now turn the airless paint sprayer on and you will see that the airless is sucking up the new paint and pumping out the primer hose. At first you will typically see a cleaning solution come out followed by your paint. When you see your paint coming out switch over the primer valve to the other position and you will see the airless pumping paint into the main hose.