-If you want to bleed the engine entirely for storage
etc be sure to do it hot. That way the thermostat is open.
-Ensuring no air pockets is similar, you need to get the thermostat open somehow. If there is air around the thermostat, the engine may overheat while not opening the thermostat. The solution is to pour hot water in where it can get to the thermostat.
Dont ask how I know this!
-Generally, the thermostat issue aside, you need to open the highest point in the hoses (like a water heater hose) to ensure the air is out.