The prep is the most important part to get good adhesion. For plastic surfaces I like to roughen the surface with 220 grit wet paper and or a scotchbrite pad. For metal surfaces I blast with 120 grit aluminum oxide. I use lacquer thinner and then finish with TruStrip to remove any oils that might be present. Best to handle objects with latex or nitrile gloves.
Here's a build of mine I practiced on the skins with over the weekend.
Most likely going to do a multicamish finish on the complete rig in the near future.