Copied this over from another thread:
1) If you are planning on painting any PE parts, make sure you clean them first to take off any oils. They can be hand painted or airbrushed with either enamels or acrylics - whether you hand paint them or airbrush them will depend on the size of piece involved and your skill. Some people recommend priming and also doing some LIGHT sanding to rough up the surface to make a better bond with the paint - I've never done either. This ONLY applies to the PE sets that are NOT pre-painted - those can be used without any prep.
2) You want to attach them using a
CA glue, in particular a slow drying CA glue so you have time to position the piece(s) where you want them. when the CA dries you can always go back and touch up any overrun on the glue if necessary. Note that CA glue applied to a painted surface will actually bond with the PAINT and not the underlying surface. If you need to detach a glue PE part, you can use a CA debonder. If will dissolve the CA joint in a hardbeat but it turns any paint it touches into goo.
3) If a unpainted piece needs to be bent, bend it first and THEN paint it. It prevents you from marring the paint with tweezers while bending it and it also removes any chance that the paint will chip or flake if you bend it after it's painted. There are special tools available for bending PE parts but you can get by with a good pair of flat tweezers. Similiarly, bend any parts BEFORE gluing them in place. It minimizes any chances of the bond breaking.
4) You will, more likely than not, suffer an occassional mishap where your PE part will pop out of your tweezers (accompanied by the dreaded SPROING) and fly into the carpet. In most cases, that part is gone forever - or at least til the vacuum cleaner sucks it up. I bought a large black piece of construction paper to put under my workbench to catch PE parts (just in case mind you) and have managed to find a couple that way.
I especially like PE for seatbelts, instrument panels, and rudder pedals.
5) Almost forgot - you can preview the instructions (in pdf format) for almost all of the Eduard photoetch sets to see what the installation entails. Looking at the instructions before you buy the set gives you a heads-up on much part grinding, cutting and bending you will need to do. That way you will have a preview of whether you are getting in over your head or not and can save a lot of headaches down the road.
Hope that helps.