Biggest thing to remember is to PREP you surface. After you have scuffed your surface, use a degreaser/dewaxer to get all the goopy bits (even ones you cant see and feel) off. Foregoing this step will cause your paint to not stick and look spotty.
Also, painting your metal bits is not a bad thing. Sure, powder coat looks great and is super durable, but, if prepped and sprayed properly, paint can look really nice as well. I have painted my Cobra highway bar black (started chrome, boooo Cobra) and I painted my stock mirrors. Both turned out great.
You can't shake the devil's hand and say you're only kidding.
2011 900 Custom SE
Cobra Swept Exhaust - Black
Cobra PowrFlo Air Kit - Black
Cobra Freeway Bar - Black (painted)
Kuryakyn ISO Grips - Black
Kuryakyn Contour Throttle Boss - Black