Dry and dusty - a clean and lube as required. Not very often.
Wet and a bit muddy - a clean and lube as required - maybe every few rides.
Seriously muddy - a clean and lube as required - maybe every ride or two.
Should check things before every ride, but I do all my own work so just when I feel the need. Nothing's ever fallen off.
So what comprises a full clean and lube. I hose all the mud off wash frame/seats/bars etc with soapy water, hose again and then lube the chain and wd40 (or what ever its called now) the front and rear mechs.
Anything else I should be doing?