While the saga of the prisoner of the galactic patrol ends in Dragon Ball Super, we can already talk about the future scenarios of this universe. The expansion that the Midquel brings in Dragon Ball is not yet easy to define, and because of this, we could see both old enemies and new rivals in the next saga.
What is certain, however, is that the Z fighters are weak. Yamcha, Krillin, Tenshinhan and the others are in great difficulty. Even people like Gohan and Piccolo cannot do anything about enemy lieutenants without pestering the chiefs of the occasion. And that's why everyone should learn three basic techniques.
After training on the planet of King Kaioh, Everyone should learn to control the Kaioken. Her strength is superior to that of Goku during the Saiyan saga, and consequently her physique should be trained to support at least three or four times the weight of this technique.
The absorption and use of energy is again at the heart of Dragon Ball Super as Molo can absorb and strengthen it. For this it is important to learn how to use it and maybe even how to learn it concentrate it in a Genkidama. So the training with King Kaioh has to be completed again to show its fruits.
Finally, the third is technique that is actually not a technique full development of the potential. Gohan has suffered this twice already, first in Namek with the great sage and then with the help of the great Kaioshin during the Majin Buu saga. His power has become very high even without turning into Super Saiyan. If the others were also to suffer from the effects of the technique of the Supreme, they would become far stronger and more capable in battle.
It is impossible for anyone to control Ultra Instinct outside of Goku. The protagonist is already having trouble with it and may be the only one at the moment Vegeta has a glimmer of ways to get it. But it is impossible for others to reach a divine plane.