This video, via spoon master Simon Glenister, demonstrates how you can use spoons to play the synthesizer. 

Glenister has a spoon tutorial site – but he also provided a short summary of technique for getting started:

• Step 1 Hold the bottom spoon Place one spoon facedown between the index and middle fingers on your dominant hand. Wrap your middle finger around the back of the spoon’s handle, and press the handle’s edge against your palm. Rest the middle of the handle on the knuckle of your middle finger.
• Step 2 Add the top spoon Place the other spoon faceup between your thumb and index finger. Wrap your index finger around the back of the spoon’s handle, pressing the handle’s edge against your palm. Press your thumb over the handle to secure the spoon, keeping about 1/2 inch between the spoons’ bowls.
• Step 3 Sit down Sit on a chair with your feet on the floor, and your non-dominant hand a few inches above your leg, palm facing down. Then, place the spoons between your non-dominant hand and your leg.
• Step 4 Play a basic rhythm Move your dominant hand up and down at an even tempo, hitting the top spoon against your non-dominant hand and the bottom spoon against your leg — the backs of the spoons will hit together to make sound. Hit up or down harder to accent the beat.
• Step 5 Get down with the gallop Spice up your rhythm; as you move the spoons towards your knee, hook your non-dominant hand’s middle finger under the bottom spoon, so it catches the utensil slightly and creates a galloping sound.
• Step 6 Try the rake To produce a drum-roll effect, turn your non-dominant hand so the thumb points upward, spread the fingers apart, and rake the spoons downward across them. Then, combine each technique to play the spoons in rhythms that’ll inspire