Clicker is good
We do "positive reinforcement" which is the same as clicker, just without the clicker. We just say "YES!" This is especially good for training tricks but is also great for loose leash walking and everything else. They may also encourage the NILIF (Nothing in life is free) which means you ask your dog to do something, like sit, before you feed them, throw their toy, etc. It teaches them patience and establishes you as the leader (not "pack" leader, just as in you control the resources). So far it's worked very well for us. I find that Loki looks forward to "homework" and going to class and he enjoys earning rewards!