1. Sit on a bench (or stand) and hold two dumbbells in front of your upper chest with your palms facing inward and your elbows bent. Your elbows should be tucked in next to your torso
2. Raise the dumbbells overhead and at the same time, rotate your palms so that they face out. The dumbbells should follow a straight up and down corkscrew pattern rather than arcing out to the sides
3. Lower the dumbbells back to the starting position, rotating your palms inward as you bring them to your chest.
Note: this is a similar movement to a standard shoulder press but with a more full range of motion so you might need to go lighter than your shoulder press.