I'm starting to use braid more as a main line. How long of a flouro leader to most of you use? Also, does the leader length need to be longer for some techniques, ie, cranks, flipping?

Well IMO opinion most of the time you don't need to bother to use a leader with the reaction baits like cranks, spinner baits and chatter baits. Tacticalbassin.com has some great tips and videos for using braid on all your rods. he has a detailed video showing the knot he uses. I just throw braid to floro on my spinning rods and I usually use a long leader 8-12ft and reel through the guides.

I like my knot to be between the reel and the first eye with about 2-3 feet past the tip of rod, so I would say approx 5-6 feet, I do not use a leader on moving baits, I use the crazy Alberto knot.

I've used Braid exclusively for awhile to test it out. Now, I'm putting on a short Flouro leader on some for testing. Crankbaits sometimes tangle Braid around the trebles and cause a mess so I put on a 3' leader and really cleaned things up. I don't buy into the line-shy argument 'cause if the Bass won't bite because they see Braid, what about 2 treble hooks dangling, plus a bug plastic lip with a split ring, and how about that hard plastic crankbait that really does not swim like a minnow? I know confidence is big ang I've caught fish in every type lure made while using straight Braid.
I will always keep trying new methods and I like the leader idea for some applications, but mostly it's the right presentation to a fish that is actually where you are throwing.
To answer your question, I go 2' to 5' but no longer.