I think the minimum hours thing depends on whether you're doing the combined CPL/MEP or not. Almost everyone I've seen go that route has taken way more hours than those who took it in a single.
My humble advice would be to practice things like:
VFR navigation. Everyone in the real world uses GPS, but keep on top of timings, your preferred course correction technique (closing angle is easy to use, but some still retain a fetish for things like 1in60).
Diversions. Try and learn to do them without rulers and protractors. If you drop your gear during the test you're stuffed. Draw a freehand line on the chart, guestimate the heading and turn onto it, then deal with things like ETAs and wind corrections. If you feel you can't cope without rulers, use a combined ruler/protractor like those available from Pooleys.
Position fixes. Get yourself some VORTRACs from Transair and affix one to each VOR in the test area. They make the task a doddle.
Tolerances. Try to keep yourself as accurate as possible in terms of heading and altitude. +/- 50ft and 5deg isn't too hard in calm conditions.
Memorise emergency procedures and don't forget the verbal briefs before take-off (how the seatbelts work, where the first aid kit is, what you'll do in the event of an EFATO etc).
Don't forget to put the gear down.