Clean all the electrical connections with Deoxit, flush the radiator inside and out(there can be a lot of bugs blocking the airflow), lube the clutch splines every 3-4 years, check valve clearance every 3-4 years, run two tanks with a half bottle of Techron in each through the injectors once a year.
Change transmission and final drive oil every two years as well as the coolant(60%water 40% coolant). Drain and fill the forks every two years as well.
Once a year, take an hour and check the torque on all the drive train and fork bolts and screws. It wouldn't hurt to put a little copper anti-seize in the threads, either if you aren't sure they have it.
It goes without saying that keeping the bike clean helps keep it reliable.