first time weathering question

ok so im done with making my first helmet (ok mostly done) and im ready to paint so i put a metallic base down and im planning on clear coating it to death then painting two more colors over that then sanding the "weathered" areas then clear coating it all again... will this work? is there a better way? i could use the advice of all you weather-ers out there :)

ok so what im looking for is some advice on subtractive weathering specifically ... no one seems to be on right now so im bumping this in hopes of a response