There are some tactics that are useful for several different units or need to be considered for the whole army.
Became the basic Tau weapon is so good, you do not need as much heavy support in low point games ( under 1000 points ).
The Tau drones are a very useful addition to a unit. You will find that most units can have additional drones attached. In the 2013 Tau Codex the range of drones available have been expanded. Have a look at each type and play with the combinations to find a mix that works for you.
The Tau troops have a great standard ranged weapon, but they are very weak when it comes to close combat. For this reason the best tactic is usually to hold back and gun down the enemy as they approach.
For an effective gun line you will want to set up where you have a good line of sight to where the enemy may come from, and hopefully a nice open ‘ kill Zone ‘ between the enemy and yourself.
Arrange the units so that they can give each other supporting fire. Wiping out whole units at a time will mean that there will be fewer attacking units in the long run. This means that you will want to focus your fire on key enemy units with several of your units in the same round.
If the enemy have a number of template ranges weapons be careful to hide behind cover if you can, and not to bunch up too tightly.
Supporting Fire is a new rule that applies to most of the Tau army and allows units to offer supporting overwatch fire to other units in 6″. As the many Tau units can take Counterfire Defence System upgrades ( Tau Codex P68 ) that allow them to overwatch using BS5, this can offer a devastating amout of fire upon charging
Another example of Tau technology is the markerlight system. These are fired in the same way as regular shooting weapons, but they do not cause damage themselves. Instead they allow other models with bigger weapons to hit more effectively, for example increasing the shooters BS, or adding ‘ ignore cover ‘ for that turn to weapons that
would otherwise allow a cover save.