Hints

Degrease bike really well with Gunk or Jizer, pour some into an old bowl and use an old paintbrush to work it in well.

Wash the bike with car shampoo really well, use an old toothbrush to get in awkward areas. Hose off with clean water.

When dry and clean and looking at its best then:-

Polish tank/mudguards/seat surround with car polish
wipe over rubber (inc sides of tyres) and black plastic with Armour all protectarant.

Put a large dob of Vaseline into a metal tin/tray and heat up till vaseline is liquid (be carefull it is very flammable)
Paint the now liquid Vaseline onto all nuts/bolts brackets/frame bits and anywhere that gets road crap on.

Now spray all the bike except brakes/tyres/seat/lights with WD40, do it so it is dripping off the bike. Don't be afraid to spray lots on.

Lube your chain really well (after cleaning it)

That's it now you can ride it for weeks in-between cleaning it and it should come up like new, the Vaseline can be a pig to get off but at least your bike is not corroding.