Apart from daphnia, i also treat my fish once a week or so to freshly hatched brine shrimp and earthworms. Hatching brine shrimp is really simple and most fish, certainly the smaller tetra sized ones, love it. The brine shrimp eggs do cost a bit but you only use very small amounts at a time so its live food at a minimum cost and no on-going culturing hassles. Just make sure you feed all the baby shrimp as soon as they have hatched as their nutritional value decreases after they hatch.
Earthworms- outside in garden i leave out a couple of plastic sheets and old mats. I collect worms from underneath. The worms get chopped up and grinded. The more you grind the smaller the pieces of flesh left. I then rinse everything through a sieve which is necessary as this gets rid of the earth which was previously inside the worms. A bit yukky but yet another way to provide excellent 'live' food for the fish without the need to maintain any cultures.