There are tons of ways to practice teching! But also remember that while teching is generally good, it's also very situational. Sometimes it's better to wait a little bit before getting off the ground, because people can read your tech-landing and punish you for it. Teching stage spikes is also very important, and somewhat difficult to do (as seen by Evo's top 8--They all missed MANY techs against stage spikes, sometimes costing them games), but teching on stage is almost a MUST, because hardly ever will a stage spike lead to anything but a lost stock! You can even practice on For Glory if you have non-laggy friends, or in training mode with a friend at 1/2 or 1/4 speed to really get the timing right!