Thanks guys! I really enjoy painting stuff (other than in winter, when I can't do it outside due to low temperatures).
I use oil-based enamel spray paints for my projects. Mostly, I prefer Rust-Oleum, as from personal experience, their sprays go on the smoothest and with high pigment density. I completely cut out Krylon, as their Fusion lfor Plastics can melt some kinds (ABS, I believe), and other kinds I tried go on too thinly and unevenly. Plus Rust-Oleums Painters Touch can be sprayed directly onto plastic as well (and many of their other paints, though I do own and use a primer for plastics in some cases). DupliColor has some good selection, but they share Sherwyn Williams as their parent company with Krylon, and I notice greater difficulty with achieving smooth results using DC too.
Moving on, for thic case, I used Rust-Oleum's Black Night Metallic as a light base coat to promote adhesion. On top, many thin layers of DupliColor Metal Speck in Silver, followed by DupliColor Clear Effex, which is a clear enamel with very fine iridescent flakes in it--invisible unless illuminated with brighter light.
Thin base layer of paint / primer, followed by slightly thicker but still fine layers of base paint. Then a fine mist of the top coat (usually a gloss clear enamel), followed by 2-3 heavier coats. Always wait at least 2-3 minutes between coats, or until they appear dry to touch. Over spraying results in pools of paint which can wrinkle, lift, and generally present problems for a smooth finish.
Polishing the clear coat is what gives that car-like shiny finish to paints without enough metal flake. Surface preparation is important as a gound for a smooth finish, but spraying from rattle cans will still result in an orange peel textured finish. So I usually wet-sand the fully dry clear coat with 1500-, then 2000-grit sand paper and follow with a rubbing compound (finer than sand paper) and a polishing compound (the finest last stage of reducing dullness and swirls). For this particular case, I did not sand /polish, and left the finish a bit rough, as it looks more like actual sand-blasted metal in person that way.
Let me know if you have any more questions!