The outside, can be cleaned much like any other car (make sure you have
a cover for the fridge exhaust/intake, so that you don't get water in
there when washing the outside). Get the under side too and get that
dirt down there.

Inside, a steam cleaner (with upholstery attachment) can help return
life to dead carpets and you might be surprised by how much dirt can
hide in the velour of the seats.

For the cabinet facings I haven't had to clean them up much. I've had
to clean the insides of some rather nasty spills from the previous
owners and have found that the Orange Pumice hand cleaner does a nice
job on that textured vinyl liner that they used on the shelves. I'm
gentle in my rubbing, so it doesn't take much effort.

Clean the INSIDE of the windows. They collect a lot of dirt too and it
isn't as apparent as the outside.

Wash your curtains. Gentle cycle (cold water I believe) of the washing
machine.

RainX your windshield. You'll wonder how you managed without it.

Clean the inside of your headlights and highbeams too while you're at
it. (Windex sloshed around inside the chamber and then let them airdry
before putting back on.)

And the door jambs are another area. You see them everytime you open a
door. Wouldn't  it look nicer if they were clean too?

When vacuuming don't forget underneath the rear bench and under the
front seats.