I'd sand off the original paint first, and thouroughly wash the entire frame.

Buying decent paint is key, as are many thin coats. I painted an old Schwinn Letour (if anyone remembers it, yes it's the one with the rear axle replacement) bright green with a brush, to save on the prep, three coats and it was themost beautiful thing I"d ever seen. I masked on lines, new decals, etc with masks I designed on computer imaging program, printed on regular computer paper, cut out VERY carefully with a scalpel, lightly brushed with Elmers, and applied. Two light coats of nornal white sprayed, let the whole thing bake dry for a day or two, and hose the bike down...the Elmer's dissolves and the paper masks flake off...the whole thing looks almost professionally done, and I spent about twelve bucks on paint and fifty cents on a brush.

If I'd REALLY wanted to make it special I'd have clearcoatedit, but I unfortunately didn't have time for that...the owner wanted his wheels back I'm gonna buy that bike someday...