I have a N. sanguinea. Here's my conditions... I have it under T5 lights, it gets a minimum of 12 hours a day. Humidity is around 65% to 75%. Highest temp: 85F. Lowest temp: 67F. I water it with distilled water only and keep it moist. I never fertilize the roots. I might put a few drops of fertilizer water that has K-lite and I put a freeze dried bloodworm in every new pitcher (the bloodworms are very small and can be found at pet stores).
---------- Post added at 11:26 PM ---------- Previous post was at 11:23 PM ----------
Forgot to add that it is currently in a peat and perlite mix and I will soon be transferring it to a sphagnum and charcoal mix. Under these conditions my small nepenthes is always putting out leaves and pitchers and it takes 8 weeks to mature a leaf and pitcher.
More light almost always help. Some species like shadier conditions, but that's a different story. I feed my Nepenthes New Life Spectrum fish food. It has calcium in it, which helps a lot in the long run, and lots of other essential nutrients.