(I put this post together in Early January and forgot to post it)
Over a year ago I took a great beginning photography course from Veronica Reeve. The main thing she focused on was shooting in Manual Mode with Natural Light. NO FLASH! She said that a picture taken with flash was like a picture of a moment that never existed. If you look at her pictures (which I think you should) You'll notice how real they feel. Its because she is amazing behind the camera without a lot of extra fluff. She says she only spends a few minutes editing and tweeking her pictures which says a lot about her skill. Any way my point is shooting in manual and flash free is hard. Especially when you are shooting in low lighting. I am no expert in this area but if you have tried shooting in manual mode with an DSLR and get easily discouraged because of low light, (like I do). Try bumping up your ISO, in the case of christmas lights you may have to raise it significantly. You definitely get a little extra noise (graininess) in your pictures but I think its worth it to capture the moment how it really is.