Navigation and diversions.
ETA's and being able to revise EAT's
Find out what aircraft you will be doing your CPL test in and get a copy of the check list.
Memorise all the checks from pre line up to runway vacate.
Line up checks
After take off checks
Climb checks
Cruise checks.
Pre decent checks
Airfield approach checks
Before landing checks
Final approach checks (RBGW) etc
After landing checks
All other checks like start and power checks plus the emergency drills you can have the check list in front of you.
Some of the emergency's drills you will need to know what to do and react quick and then you should be able to go to check list for confirmation of correct action taken.
Sounds a lot to remember but trust me after a while they all become second nature.
It never ends as I'm having to start learning extra checks now I'm doing my IR training.
pipergirl check pm