I mostly use Colorista.
Sometime I use MBL in combination with Colorista.
Usually I try a preset and strip it a bit down, tweak the curves and diffusion and then I tweak Colorista again to get the shadows and highlights I want.
Last time I did this was on this:
http://www.youtube.com/watch?v=a_le1-C1_a4
I still have MBL 1.1.
Are the controls improved since then?
Draging the curves or colors is not working properly as if there are only 3 positions to drop it.
(Changing numeric values is not as intuitive as drag and drop.)
That's why I combine it with Colorista. (Also 1.1: updates are coming soon to my new system.)
Changing to MBL from Magic Bullet Editors was quite a 'shock': somehow I had more control on the result with the old version, lol. I tried to rebuild the old neutral settings/workflow, but that didn't really work out very well....
Calibrated monitors are important (even when you don't trust then and use waveforms and scopes):
the colors will be in the safe 'center': it shows cooler on cooler monitors and warmer on warmer.
If your monitor is too cool and you grade for a warm look, it will look hotter than CSI Miami on a warm screen.
Search the bookstores for "Colorcorrection for video".
It has over 150 pages of theory, examples and tutorials on the subject, explaining scopes, waveforms and your tools to manipulate them (levels, curves, colorwheels, etc).
I know tutorials are cool in this internet-era, but most stay very superficial and teach you a trick, but no knowledge (that would be hours of Youtubevids) or skill (you need knowledge to practice skills).