SWITCH IT UP!
There is so much advice online... but it is buried behind filler.
In this short, I suggest that you should keep your games from being stale by having your enemies think tactically together with simple 'manoeuvres'.
KEEP YOUR PLAYERS GUESSING!
This is a highlight from a full video on how to improve your combat, and make your D&D, or other TTRPG, games more fun!