Standing DB biceps curls

Grab a pair of dumbbells with a neutral (palms facing in) grip and stand tall with your feet shoulder-width apart.
Extend and contract the triceps at the bottom of the rep before beginning the movement.

While holding the upper arms stationary, curl the weights forward, turning your palms forward so that your thumbs are pointing away from your body while contracting the biceps (your grip changes from neutral to underhand). Important note: don’t flex your wrist while curling the weight up – in this case you will lift the weight with the muscles of your forearm mostly.
Squeeze the biceps hard until it’s fully shortened and hold the contracted position for a second at the top. Do not swing the arms or use momentum. Keep a controlled motion at all times.

Slowly lower the weights back to the starting position.
Repeat for the recommended number of repetitions.