Object should not be super cold, can must be warm. Don't put the first coat on too thick, or try to get full coverage in one coat. First coat can be translucent, but it should be fairly even. Allow it to get slightly tacky, and go for a second coat. Make this one wet and even. You will see it ''melt'' into the tack coat. Don't get carried away, and wait a little longer for the third coat. Watch the sheen in the light, and go for a wet smooth finish. Large flat surfaces should be placed horisontal if possible.
Many thin coats added to an already tacky surface will give you a nice result. Krylon makes for a good spray pattern, Rustoleum is a wetter more substantial paint, but needs longer to tack, and has a cheaper nozzle.
Keep the nozzle square to the surface, and move the can evenly all across the object in a straight line. Pull the trigger before you get to the object, and then make your sweep. Do not stop spraying until you are past the object. Follow up with a second pass that overlaps the first by about a third to a half. Make sure it is all wet, it doesn't have to be full coverage or perfectly even. When it gets tacky, it will hold the paint better, and it will be easier to get it even without putting on too much paint and getting drips.
Practice on the back or sides of objects. You will want a real respirator for paint, and keep in mind that the overspray will be very wet, very fine, and will stick to your newly painted garage floor, car, walls, or anything within about ten feet minimum. Sandable primers that have been sanded make a GREAT base for smooth even coats, but paint like rustoleum is sticky and nasty, and will go over any sanded and degreased surface, as long as it isn't too porous. That would mean most metals and some plastics. Prime wood, remove the bulk of rust. As always, the better the prep, the better the final finish.
There are also some pretty good spray paints out there, like Wurths. If you are not happy with the results you are getting during the spraying process, STOP. SOme people can pick out a run with the edge of a paper towel. If you cannot, wait, resand and reapply. Objects must be fully dry to sand, although you can push it a hair with wet sanding.
Concentrate on getting even coats without runs. Everything else will be easy after that.
