Choose a clear trigger and target
A kick can trigger gentle reduction on a bass or music bus, while a vocal can trigger a small dip in a competing instrumental layer.
Make sure the detector responds to the intended event. Filtering the sidechain signal can help a compressor react to the kick body or transient rather than unrelated low-frequency energy.
Set attack, release and amount
A fast attack can create room for a transient, while a slower attack allows more of the initial sound through. Release time determines how quickly the gain returns.
Set release in relation to tempo and groove, then listen to the pattern rather than copying a preset. Too much reduction can make the track feel unstable or smaller.
Keep the effect in context
Bypass the compressor at matched loudness to confirm that it improves clarity or groove. If the change is not useful, simplify the setup.
Sidechain is one option among many. Arrangement, EQ, volume automation and sound selection may solve the same conflict with fewer side effects.