"Be On The Lookout" is a way to add "awareness" as an element to control risk. Although awareness is lower on a hierarchy of risk controls, it is an effective tool that can be used individually, with your team, or your crew. Pre-flight or pre-shift briefings can set-up the workgroup to be on the lookout for a particular risk or situation.
Atul Gawande - Checklist Manifesto
Flight Risk Assessment Tool (FRAT) info from the Federal Aviation administration (FAA)