just practice and the only one, most needed I would say, check the hardest maps and try to increase dmg there for higher mk tier if you are missing about 10-20% dmg, otherwise it's not worth mostly
Something that helped me a lot was getting higher max level talent book After that I managed to go from cracked glass in w3 to completing w1-w3, purple slime cubes in w4 and the 3rd or 4th map in w5 iirc Makes a crazy difference
