Baldur's Gate 3: 11 Tips & Tricks The Game Doesn't Tell You
8. Don't Miss Combat Opportunities
In Baldur's Gate 3, combat is turn-based with each character's turn consisting of a main action, bonus action, and movement action. Since you have all 3 options available each and every turn, try to make use of them.
As a fighter you'll have a high strength ability score, making the success of the 'shove' bonus action quite high when it comes to most enemies.
When you find yourself outnumbered on a high cliff, don't simply run ahead without thinking and cleave the first enemy you see. Trudge up to the enemy closest to the cliff's edge and shove them off. The only thing better than cleaving an enemy is doing it to his friend after you've pushed them from an unsurvivable height.
Another great example of Fighter-based play is to use the 'dash' action when your movement can't get you in range of an enemy. Using this will allow you to travel double the distance, and even though you won't be able to attack, you might be in a position to inflict an opportunity attack on that creature, if it decides to move past you without disengaging.
Before ending your turn, remind yourself of the things your character can do and make the most of it.