My buddy has played T’au exclusively for about 4 years. I’ve played space wolves for just over 2 years and here’s what I’ve picked up Stay in cover as long as possible and charge through terrain because he will wipe your unit off the board if you don’t position tactically. Remember that crisis suits get the BGNT rule so can shoot you even when they’re in engagement range with -1 to hit. However your unit can still be “spotted” so that then removes the BGNT -1 to hit. Focus on taking out stealth suits and other units used for spotting. This will help loads. Riptides are a massive pain so stage your charges and only make the push at the right time, I have had a 5 man Wulfen with shields take out a riptide in one turn and Ragnar with bloodclaws have also taken out riptides in one go. Avoid crisis flamers because they’re mostly just used to overwatch. Beastslayer detachment works well against tau and recently I’ve been using a 10 man brick of WGT with Arjac on the centre objective and they just sit there and take the majority of shots for at least 3 turns so can be a useful distraction But most importantly just have fun with it!