Dust2 Terrorist B Tunnel Guide

After buying equipment, immediately run towards tunnels, jumping over the ledge and prepare to enter Upper B. At this point in time, CTs can make it to the stairs on the right leading to Lower B.
The lead man should throw a flash bang into Upper B, or directly above the stairs (not at, since they could still escape). 
Be warned that this WILL warn the Cats that you are at B, and they will begin to rotate accordingly. 

The lead man should run forward, keeping his eyes on the Upper B tunnels exit to B site. Immediately, two things should happen. The man behind the leader should strafe with his gun pointed to the stairs to immediately right to engage any CTs that appear after the leader's flash bang. At the same time the flash is thrown, the third terrorist should prepare a frag grenade and toss it towards the stairs. If not fragmentation is available, simply aim in the direction of stairs. 

All 2 remaining terrorists must be ready at the side of the entrance to B
 At this time, another flash should be thrown by the leader into the entrance to B to discourage anyone trying to rush, quickly to retain numerical advantage. One of the remaining terrorists should also throw a smoke grenade as hard as they can at the wall of the tunnel, bouncing off to land in front of B platform. 

After the flash, the remaining terrorists should clear the entrance tunnels. Tthe leader must carefully bounce a flash off the outer wall (Left from T side) into B site, making sure to clear the car boxes to flash anyone at car. The two remaining terrorists must immediately push after the flashbang deafens and blinds, with the lead terrorist behind. The two terrorists watching stairs must break odd advance from behind unless already fighting (in which case, stall them from a corner such as B entrance) as tunnels little cover inside of it for Terrorists. After B site is cleared, position terrorists outside double doors, car, and back of platform, then plant.