I wash mine pretty much after every outing, unless it's dry then it might go two or three. I don't use it to commute or for work, just pleasure, so it's not too bad.
I use a pressure washer, with the lance turned down to about half, something like hose pressure. I rinse the bike first, then use snow Foam, rinse that off then use a bucket and microfibre sponge/handmit with car shampoo. Rinse it again and dry it off.
I try to point the spray from the pressure washer, mostly, down the bike from the front, in the direction the rain would hit the bike if you were riding in it. Try not to point directly at the wheel bearings or electrics.
I also use a pet dryer to finish the drying off, unless it's a nice hot sunny day then it stands out for an hour or two..............I usually use the pet dryer!!!
Then a polish with Mr. Sheen on the dash & plastics.