Tau are usually played as a static gun line army designed to wait for the enemy to come to you and gunning them down as they approach.
However, what do you do if the objectives are outside of your defensive lines? Well in this case you need to whittle down the enemy with the big guns as far as possible and then use the fast attack teams to mop up what is left.
Pathfinder Team Tactics
The Pathfinders are the Scouts of the Tau army. They get the Scout and Outflanking special rules. However the Pathfinders have a specific role in the Tau army, the lightinhup of targets with Markerlights!
Vespid Stingwing Tactics
Vespid Stingwings are the jump pack troops of the Tau Army. Instead of having Jet packs like the Crisis suits the Vespid are another alien race that have been drawn in to the Tau army.
I like the Vespid Stingwings as a good anti Space Marine strike force. At 18 points a model, and with a 18″ range weapon, they will not survive if you assault a large Space Marine unit, but if you are looking to take out a wounded unit that has strayed way from the main force, then you can swoop in an polish them off.
Drone Squadron Tactics