Paul,
There are many tips on detailing - generally they're the same as the ones you'd use on car models.
Try to paint nuts and bolts with a contrasting color, use washes to enhance visual contract, use thin wire and fishing wire to replicate wiring and tubes - usually the tubing provided in the kit is grossly overscale.
Try to have a look and take pictures of the real thing so you can see what you need to add - try contacting a dealer/distributor for access to view the real thing.
What are you planning on building?