Roll of cling film - cover all electronic and intake areas with it
Autoglym Engine & Machine Cleaner
Hose with no attachment
Assortment of old toothbrushes and bigger brushes
Terry towel
AG Vinyl & Rubber Care
Do the cling film bit, then lightly rinse the engine bay and remove the big non greasy bits you can see.
Then spray the E&MC over and agitate with the brushes.
Rinse again - check you got all the bits you wanted to
Use terry towel to wipe over and dry everything
Apply V&RC to get the finish you want on the plastics
Take for a drive to warm everything up and get rid of residue water (and then get back and wipe over again, it will have streaked! ) Just don't touch anything hot!
Oh, and start this with the engine cold.