I personally would get a copy of the CPL syllabus and train to that - eg. headings to within +/- x degrees, altitude to within +/- y ft etc.
Maybe even take an instructor every 20 hours or so to hone (?) your skills and ensure no bad habits are creeping in.
I was also advised to try and fly in the area where I am going to be doing the CPL, learning all the freq.'s for the local aerodromes, local visual features etc - study the charts etc.
Good luck
PFO