It is recommended to use 10-15 lights per foot of tree for a good balance of coverage and light intensity. Too many lights can overwhelm the tree, while too few will leave it looking dull and unappealing. Additionally, the type of light (incandescent, LED, or C7) can also affect the overall look and feel of the tree. Incandescent lights provide a warm, cozy glow, while LED lights are brighter and more modern. C7 lights are larger and more traditional in appearance.