Challenge Modes - need help

Hello,

can you help me a little with optimalizing my challenge mode group ? Which specializations would be best, which talents, glyphs and some good tips ?

Group: Blood dk, Holy paladin, Warrior, Mage, Warlock

Ofc we'll look at some gold videos.
What we know - more sockets gear = better, invisible potions, dps flask-potions
Is there something more what we could use ?
But main question is still: spec, talents, glyphs

Thank you ;)