What was your successfully CAT prep strategy?

As a working professional, what was your prep strategy for CAT?

Considering, your performance at work wasn't affected a lot and you were able to manage the study with a fixed routine.

I know, this would've been one hell of a task, to juggle all these things at once, but if you could advice some DOs and DONTs, would be appreciated by a lot of us on GV, I'm sure.