I've spent a lot of time working with the Kanger T-2. Through ECF posts, trial and error I've solved the leaks:
KEEP IT FILLED!! The other posts are right, when they get low, there is too much "air space" in the tank, it draws liquid into the tube faster. They need to stay at least 1/2 full.
Keep new coils on hand: they are $1.60/ea. at
ecigarettes | electronic Cigarettes | e-liquid. When it draws too much liquid in the tube, or they just don't perform like new, swap out for a new coil. I rinse the old ones, save for another time. I have never had one completely quit working, they just degreade in performance.
OF COURSE: Rinse occasionally, keep all threads and caps snug, keep them standing upright to reduce the chance of liquid seeping through the coil when lying horizontial.
Keeping them mostly filled seemed to be the best tip, the leaking started when the juice was low.
A friend was told "press the button a second or two prior to taking a hit, that burns off alittle juice", and "draw slow, don't overpower the tank with a big vacuum hit". I don't know about the button press, but a slower hit helped a little.