Spray Painting with Sticks
For spray-painting, you can get a stick (or even a tooth-pick), and attach an end of it to an un-exposed portion of the part you are about to paint.
You can then hold the stick and spray the piece to be painted. After that, stick the other end of the stick into a piece of styrofoam and leave to dry.
It's a little more time-consuming... but it's clean and you can handle your parts without being afraid of messing up the paintwork. :)
credit : http://gundam_base.tripod.com/
