The best way to learn flow is to force yourself to work left to right top to bottom. Do not ever back track to clean something you have passed. Once you have moved on it’s a goner! Move with flow in an entire room cleaning as fast as possible. After you have finished an entire room (minus floors) go back and check your work and make corrections. Do this for every room in a house and note what you are missing. You’ll find that you keep missing the same little things and eventually train yourself to work quick without wearing yourself out.