The pitot is connected to the airspeed indicator (along with a static source). Make sure nothing is stuck in there that will restrict the flow of air, otherwise the airspeed indicator may not function properly.
Check that the bees haven't built a nest overnight. Otherwise you'll get a nasty surprise when you open the vent in flight!
For daytime flight you might just check that the lights seem secure. For nighttime flight you want to turn them on briefly to check that both bulbs are working. Robinson has a (pain in the butt) lockout system so that the landing lights don't work unless the clutch switch is in the "engage" position. To check the lights I use this procedure: