saw a thread before but cant find it now. Can anyone give me a simple steps guide to painting order for plastics?

just the straightforward

sand,
prime,
sand,
paint
etc??

to get the best looking finish.

Im also wanting to colour code some mesh.....is this easy to do? to the same sanding etc rules apply?? and does mesh need primer and lacquer on top??
HELP!!

 

can anyone help?? or point me to a thread/site that gives me some info??