Something I'd strongly recommend on a basic level without getting into combos is *positioning* and *predictability*.
Predictability:
Good players can predict other players movement, sometimes thoughts or at least thought patterns. If your movement becomes unpredictable, you can get out of crazy situations and win unfavorable fights.
Positioning:
Position yourself **intentionally**, don't just run around the map and get kills. Use the map to your advantage, anything from higher ground/lower ground (situational), using blocks for cover or to control their movement, just have situational awareness and use the little things for your advantage! It sorta goes into spacing.... But that gets deeper into the PVP realm :)
If you'd like to practice, you can always add me on discord to play some games or practice. Just give me a heads-up username: officialcci9
Hope this helps!! :)