Ted Holowchuck is truly gifted when it comes to painting, whether it's the exterior or interior of a model. Here's an outline of his procedure for painting aircraft cockpits. As you can see from the 1/48 P-40 cockpit above, the results are truly magnificent.
Raw plastic or resin.
Spray-paint with appropriate interior color (interior green color in this case).
Drybrush with interior color that is lightened (with yellow in this case) to highlight raised edges.
Brush paint all 'black boxes' and appropriate panels with 'lightened' black (do not use straight black but a dark gray instead).
Drybrush 'black boxes' and panels with a lightened version of base dark gray color. This will highlight the 'black boxes'. Also, brush paint the rest of the interior parts, such as wires, cables, lights, knobs, switches and map panels. Use colors such as brown, blue, red, yellow, white, gray, etc. This will add color, interest and a busy look to the interior.
Spray a coat of clear gloss lacquer.
Wash all painted interior parts with an oil base wash color, using black and raw umber oil colors. Allow the wash to set up, then use a dry cloth to wipe off any excess wash. This step adds depth to the painted parts. When dry (24 hours) apply any placard decals.
Spray a coat of flat finish (dull coat).
Drybrush selected areas with silver to replicate chipped paint and wear. Go easy with the silver. Use appropriate colors (gray, blue, red, etc.) to touch up knobs, switches, etc.
Touch up instrument dials, indicator lights and some switches/knobs with Kristal Kleer or 5-minute epoxy.