Yeah I agree with tmpffisch 100%!
Make sure you do your CLEAROFF checks atleast every 5 minutes or so, or whenever you feel you need to.
Having a good LAP(Lookout - Attitude - Performance) cycle will definitely give you a good scan outside and inside the cockpit.
A very usefull check i always love to use is the WANDER check. This check is great for an unexpected inflight diversion:
W-Wind/Weather (Most importantly, where's the wind coming from?)
A-Airspace (do you need a clearance to transit?)
N-NOTAMs
D-Daylight (when is the EOD?)
E-Endurance (Have you got enough fuel for the diversion?)
R-Radio (Do i need a clearance OR amend a flight plan OR amend a SARTIME? etc.)
Just a little something.
In Out.