Seeds keep cooking in a hot pan even after you turn off the burner. That is why a batch can look perfect at the stove and taste bitter by the time it reaches the salad.
Use moderate heat and stir or shake the pan as needed. Watch for a little color and a toasted smell, then transfer the seeds to a cool plate instead of leaving them in the hot pan.
Toast only a manageable amount while learning how your stove behaves. A deep pile cooks unevenly and makes the lower layer difficult to inspect. If adding spices, remember that fine powders can burn before the seeds are ready.
Cool before sealing any remainder in a container, following suitable storage for the ingredients. For a shared meal, identify the seeds rather than assuming a small garnish is irrelevant to somebody with an allergy.