Some of my favourite posts on other sites are the 'how to beat army X' articles. If you don't have access to players or clubs where the latest power builds are played, being able to read up on how they work and how to approach them gives you a much better chance of forming a plan on how you're going to tackle them.
For Tau, recognising their typical weaknesses, such as limited mobility outside of jump suits, general reliance on riptides or allies for contesting/scoring distant objectives, vulnerable ethereals giving up a potentially game changing VP (think Relic and Emperors Will) and relatively squishy troops, means that you can consider how best to place objective markers, deploy your army and set up your target priority through the game.
Matt-Shadowlord does a great job of discussing these points and more over on 3++ here and here. Well worth a look if you haven't already!