I've had success with a couple rattle can jobs and I'm in the process of a third. I agree the key is prep work. I usually start with a strong paint stripper, then finish with a combination of wire brushes and sanding paper. Also a good idea to have careful planning for the actual spray work. Best to get it done quickly once you're ready to lay down the paint, meaning, the more time from stripped frame, through primer, color, and clear, the more likely something can go wrong, including picking up dust, finger oils, or other contaminants, and well as ordinary clumsiness.

I've only used automotive paint in a can for frame painting. It's a bit more expensive but I'm willing to spend a little extra on more durable paint considering all the work that is involved. Most auto paint stores will have a huge variety of colors. If matching colors, take the color book outside and view against a sample in the daylight.

Don't skimp on protective gear. No sense restoring a bike to ride, in part, for your health if you are going to inhale toxins in the process.

Pick a good day to paint. If possible do it on a day that's not too cold, hot, windy or humid.

Multiple thin layers of primer, followed by careful sanding when dry, then multiple layers of color, followed by more sanding when dry, decals, multiple layers of clear followed by more sanding, time to cure, and done. Basically like this (minus the sandblasting and shipping): Joe Bell: Painting a Frame, Step by Step

Best to go with several thin layers rather than linger with the can over hard to reach areas (such as the BB shell) which can lead to runs. It's okay if the first coat is mostly a misting with emphasis on the lugs. The main tubes are easiest to fill in later.

Letting the rattle cans sit in warm water prior to spraying can help with paint flow.

Make sure whatever you use to hang the frame while painting is secure. You don't want it falling while the paint is still wet.