Here is what I usually do with my cockpits:
First, I painted the main color (interior green,zinc chromate, ect.)
then I use a double tip black Sharpie permanent marker for the instrument boxes and the panel, since most aircraft had those painted in black or drak gray. Then work some details in drybrushing with gray or steel. Use clear nail polish for the instrument dials
Then try the same techniques on hoses,wires and other details for more realism.
It may not solve all your problems, but I'm sure it can help