Swinging the weights
Use lighter dumbbells and lift with the shoulders, not a hip or knee bounce.
Isolation · Dumbbells
The dumbbell lateral raise lifts the arms out to the sides to about shoulder height. It is the most direct exercise for the side delts, which give the shoulders width, and suits anyone who wants broader-looking shoulders.
The side delts raise the arm out to the side. The upper traps assist if you shrug or go far above shoulder height, so keep the shoulders down to keep the work on the delts.
Use lighter dumbbells and lift with the shoulders, not a hip or knee bounce.
Keep shoulders down and think about pushing the dumbbells out to the walls.
Pick a weight you can raise to shoulder height for 12-20 controlled reps.
Surpass starts the lateral raise at 12–20 reps with about 1 reps in reserve. As an isolation exercise it fits well after your main compound lifts.
Progress reps in a 12-20 range before moving up, since even a 5 lb jump is a large percentage increase. Add sets over time and consider cable raises for more even tension.
Surpass shows what you lifted last time beside a target for this set, and adjusts it from your reps and RIR. Free on iPhone, no account needed.
These train the same main muscles. Swap when the equipment is busy, something hurts, or progress has stalled for several weeks.
Lighter than most people think. A weight you can lift strictly to shoulder height for 12-20 reps works far better than heavy swinging.
Shoulder height is a good stopping point for most people. Going higher brings in more upper traps, which is fine if comfortable but not needed for side delts.