Combat becomes easier when you solve the battlefield before you solve the build. Positioning and target access can matter as much as raw damage.
Start from useful positions
Elevation, chokepoints and distance can change how much value each action creates.
Focus dangerous targets first
Reducing the number of threats can be more valuable than spreading damage across several enemies.
Save limited resources for moments that matter
Strong abilities are useful when they prevent major damage or end a dangerous turn quickly.
Use the environment
Terrain and hazards can create advantages that no character respec is required to unlock.