Be sure not to lock your elbows at the top of the lift, and don't let the dumbbells touch.
Remember to breathe - exhale when lifting up, and inhale when recovering back down.
If you're just starting out with dumbbells, progress from: seated with back support - to seated without support - to standing.
For even more precision and control, try lifting each dumbbell 1 at-a-time.
Make things more interesting by doing the shoulder press whilst sitting on an exercise ball.
Although the shoulder press is a great exercise on its own, it's still only really working 1 joint - your shoulders. Great for if you're returning from injury or you need to isolate those muscles for any reason.
But as always, the more efficient workouts are where you're using multiple joints and muscle groups. This variation with squats is exactly that.
Stand with feet shoulder width apart, hold each dumbbell at head height (upper arms parallel to the floor, elbows bent at 90 degrees) and palms facing forward.
Squat down half way by leaning your hips slightly forward, bending your knees, pointing your bum backwards and keeping your back neutral.
Then squeeze your quads and push up through your feet, legs and bottom. Keep the movement going straight into the press (described above).
Complete the press, returning to your starting position before going into the next squat.
Tips: Keep control of your movement throughout the exercise. If you lose balance, slow it down. Remember slow, steady lifts with good technique will produce faster results and keep you injury free.
Shoulder Press Videos
Enjoy this dumbbell exercise! Check out these great videos that'll give you a visual idea of the best technique: