Another way to feed is to use frozen or live foods. If you feed frozen foods you can feed purely frozen if you fortify with a vitamin supplement like Vita-chem. I really love feeding frozen because it has such a high and easy digestibility factor. If you don't add vitamins you need to keep feeding pellets though because you will be missing certain vitamins and minerals.
Another trick would be to put a couple drops of garlic juice into the water. This causes most bettas to go into a feeding frenzy!