Prep and Patience
Prep and patience is the key to a good home paint job. Overzealous spraying is your enemy. My motto is like the cologne technique, "Spray and walk away."
I don't paint my own stuff anymore because I prefer the durability of powder coating.
But when I did paint my own stuff, I had decent success, but nothing ever looked pro though.
Tools/Supplies: Krylon or Rustoleum spray paint of choice, sand paper (rough and finishing grade, alcohol or any cleansing prep product, coat hanger or wires to hang frame during painting.
1. Sand off existing clear coat
2. Remove decals
3. Lightly sand exising paint to rough up texture, but do not sand down to metal.
4. Clean surface with cheap rubbing alcohol or product from store
5. Spray light coats and let dry (30min-45mins)
6. Spray second light coat and let dry for a day
7. Lightly sand to remove any kind of drippage
8. Spray third coat and allow to dry for about a day or two
9. Clear coat is optional
This was my technique in high school on my BMX bikes. Worked decently, but like I said it was never stellar. Choose a dust free and breeze free area, yet still ventilated.
You don't need a sprayer really. I always used shaker spray cans.
There is a post here recently called "Paintjob tight wad style" or something like that. Do a seach for it, the poster painted a blue frame and it looked pretty good in the thread photos.