yeah, the pre-flight inspection idea is a good one. but, if you ride your bike every day, it becomes a bit burdensome.
i'd say it's a good idea if you only ride once a weekend or something, but my DRZ (daily commuter) only gets a thorough pre-flight every month or so.
no oil on the ground under it? check.
tires are not completely flat? check.
brakes work OK as i' getting on it? check.
starts up? check
i'm good to go...
(it's obvious if the head light is not working and i do check to make sure the tail light is working every now and then.)