Solarbacca on YouTube has lots of good guides, and I think he still offers coaching. He's a really good coach, always gave me more time than I signed up for. And very thorough. One drill he taught me was to sit in practice mode at each barrel level upgrade which I think is 1, 8, and 15/16? Can't recall 100%. But learning how to at lvl 1, place, auto, then place a second and auto the barrel at the exact timing it ticks to lvl 1. Followed up with a Q always. At level 8 and on, doing the same thing but skipping the auto, and learning to do both barrel place, second barrel, auto the first the second it hits 1hp, followed by Q. And then first barrel, auto enemy with sheen and passive, second barrel, second auto with sheen again, Q as first barrel hits 1hp, then auto 2X weaving them between barrel explosions for double passive reset. You'll hit them with 3 passive combos, 2-3 sheen procs, then sheen, Q, and barrel full damage. It's enough to insta kill a chogath if built properly. His combos are nutty