OK since no one answered it. I'll share some of my knowledge with you. There are a few schools of thought on how to hold novas/photons. Here are some basic ones. You will need to change your finger placement so it is more comfortable for you, but these how I have either done it in the past or seen others do it.
2 per hand:
Most basic form, 2 back to back. Use your thumb for one color and your index for the other. Usually it is easier to use the knuckle of the index unless you feel comfortable pressing it another way. Usually this is for easy control and for people with a little less dexterity. You make also use a strip of tape wrapped around both to hold them together if you have a problem. Another solution I have used when learning is to use velcro.
Same as above but for people with a little more finger dexterity. Usually the top is easier since it allows you to have more pressure against photon since your index finger is sideways so it gives more stability.
This is based of the "wolverine" form. The index figure is used merely as a "board" and the thumb and middle finger press the photon. The idea here is to keep the index stiff as possible and press the photons into your index.
If you master anyone of the above, the next step is 3 lights. Here are 2 of the more common styles.
3 per hand:
Based on the first form above, you merely insert the 3rd photon between the index and middle finger. I like to use the middle knuckle to press the button as it is a little bit easier to press the button down since you use the bone rather than the soft tissue of your finger. The first 2 work the same as the first picture.
A slightly more complicated 3 photon form, based of of the "wolverine" form that most people tend to use but will keep there leds on the whole time. With this style you should be able to turn on and off any led and anytime, while still maintaining a decent distance between the lights themselves. The form above has the first 2 lights very close together, so you often have to use high contrasting colors. As for this form, it requires a lot more dexterity especially in the ring finger. The first photon is controlled like normal between the thumb and index, the 2nd is using the middle knuckle and index knuckle, the 3rd uses the middle knuckle and ring finger knuckle.
You will need to play around with each form a little to see what is most comfortable. Some times you may need to turn the photons of your fingers to get them right, it takes a little bit of practice to get comfortable with them. So don't give up to quickly. Should you have the need to learn more, I can teach you up to 5 led's per hand, but note it requires a lot of finger dexterity since the last photons is controlled with the pinky finger. Hope this helps. Good luck.