I don't spend a fortune on buying new decorations each year, but I do have a few suggestions for decorations that look good and don't cost a packet. You'll find some good little home made Christmas tips here.
You'll see tea lights feature a lot. I find the best value and best choice locally for me is at Homebase, Kendal. You can see what Homebase have to offer here.
For a truly great and inspirational set of candle, lights and other Christmas decorations, look at old favourite John Lewis. As I love John Lewis but don't live anywhere near a store, I use the online order service a lot, and it's excellent.