pusga's boomhit tutorial is naic
as for openers, it's a rather gray area. anything that works and that can get you momentum, will work. if an opener is bad, people will look past that and judge the rest of the replay accordingly
(unless your like an ormo recruiter or something heaaeahahaha)
you have to know how momentum works, and how to gain it. also, know about inertia. what?! physics in a broken glitchy game like toribash? no way!1
well inertia does apply. (when i say inertia, in case you don't know, is the resistance something has against moving). when you kick, you want to move your body parts in the opposite direction of it's line of movement. pretend the foot creates a trail, and the direction that trail goes in, you want your arms, and other leg, to go the other direction. rotating your chest plays a BIG role in this.
don't be afraid to try something out of your style. punching does exist. when you start stemming out from your style, that's where you start getting creative.
this is all i could think of for the time being, so i hope you find it helpful