The Standing Single Arm Shoulder Press is a great exercise for increasing upper body strength, particularly the shoulders, anterior core and obliques.
In order to perform a Standing Single Arm Shoulder Press you should stand with your feet hip width apart and bring hold your weight at a 45 degree angle away from your body. Raise your arm up bringing your palm to face forwards at the top. Then lower your arm back down to the 45 degree angle position.
Throughout the exercise it is important to ensure minimal movement through the rest of your body. This is achieved through engaging through the core. If you find that you have a lot of movement across the body, you should try using a slightly lighter weight.