Combos
Real-time combo driven combat is combined with the classic MMO staple, hotkeys. Mashing the mouse buttons or combining inputs to make for heavy attacks is enjoyable and effective against starting enemies, but once you invest points into skill trees and fight tougher enemies, you’ll want to make sure that every upgrade and new skill you unlock will work into your combos. Those who randomly click around on the skill tree will waste points and have a tougher time during combat. It’s also important know that of the skills that you have, there are more effective orders to use them in than others. Experiment with early enemies to find out which combos are the most efficient, and remember them when fighting those who will actually give you a challenge. 
Knowledge
Not BS Tai Lopez knowledge, I mean the in-game mechanic. Knowledge acts as both a glossary of sorts for all the details about the lore, world, enemies, items, etc; but most important of all are the enemies, because until you earn enough knowledge about a certain foe, you won’t be able to track their health status in combat. Multiple things can be done to earn knowledge, with the two most effective means being to fight against certain enemies repeatedly, and to speak with every NPC you can find.