FIRST MAKE SURE YOUR ENGINE IS COOL
If you have an intake, cover the filter with some plastic bags(rubberband them on) and cover electrical connections....
Use a cleaner like Meguiars Extra or Simple Green ... spray down the engine bay... let the product sit for a few seconds and work the tough areas with a brush. Hose off the cleaner (dont use a spray attachment). Reapply the cleaner and scrub and problem areas that are still there.
For your rubber hoses you can use Mothers Back To Black or ....any instant detailer (which also works well for Hose Techniques).
If you have polished pieces (intake pipes, oil caps, etc) use some Mothers Mag and Aluminum Polish. Follow the products directions --- use a 100% Terry Towel ... MADE IN THE USA ... that way you know its a high quality terry... polish in a side to side motion .... polishing in circles can actually be seen on the metal!
If you have chrome (valve covers, manifold shields, etc) ... a good chrome polish like Mothers Chrome Polish works well. Apply with a micro fiber towel, let dry, then buff off with a clean section of towel.
If you really like a shiny engine bay --- No Touch Tire Foam is your best bet .... cover up stuff you have polished/chromed ... spray the engine down .... before it dries, wipe up any excess -- a little goes a long way. Make a note tho .. this will attract more dust so you will have to clean your engine bay more often. I only do this for shows.
Pe@ce