Which of gokus moves aren't used enough?

MULTIFORM

Goku really needs to learn some new techniques instead of just transformations. The last combat technique he learned was IT, and the last "support" technique for lack of a better term, was Fusion Dance. Learning to use Kaioken alongside SSjB is neat, maybe he can do Spirit Bomb in that form now as well, but rather than variations and new uses I would prefer something new altogether for combat. Gotenks was like the exact opposite of Goku, tons of new tricks all the time but Goku stagnates, and that's a little too similar to how Superman is for my taste.

I don't have a lot of suggestion, it can't be easy to come up with stuff and properly implement it all, but I've always thought that, at the very least, the Z Fighters should train together and swap moves and techniques. Everyone should be using Kaioken and Instant Transmission by default now, and I don't see why everyone isn't begging Tien to learn the Tribeam.

As for one idea, I'd like some type of dimensional techniques, like Goku could fire ki through space and it could end up elsewhere, kind of like Janemba.