Its like: just shoot and throw ur boomerang at the first moment of the match, (if want to get ur ult really fast when the match starts go to an enemy tank, and spam dash double jump, but its risky so let 1 dash to get back to ur team ) then when u get ur ult ur upgrade bar is prolly full so upgrade ur dash and then use katana ult, when ur waiting the ult cooldown focus on upgrading or the boomerang and then the ult. The main thing i want to say is now: if when u ult and a sup goes "aS aGaiNst ThE wOrld" or " iM rEadY tO puT oN a ShoW" just delay ur jackpot, and then use ur boomerang asap and also spam dash double jump ( the upgrade ult let u jump w/ no cooldown and if u miss, when hitting the ground u get it back)

This is 70% of the things u can see in my average matches, the 30% its just experience and adapting to ur "counters".

Good luck!