I prefere not to use a pressure washer. If you wash it by hand you are more likely to spot anything amis whilst washing it. Such as loose bolts and stuff. If you do decide to use the pressure washer route, be gentle on the brakes and the chain. Hi pressure can cause damage to seals etc etc.
I have always found WD40 to be great for cleaning anything on the bike (apart from the brakes and surrounding area, ie disks.) I give it a soapy wash first to get rid of the road muck and then WD40 for those more difficult to shift bits of grime.
Finish off with a nice polish.
If you need to speak to an expert on how to clean your bike have a word with Jonboy. He's the master
