BH & G recommends: First, the lights.
Yes, many of us have pre-lit trees, but some of us might consider adding more, and others are decorating a real tree this year.
Sparkle and shine comes primarily from the tree lights. Faceted glass bulbs will refract more light and appear brighter.
Small twinkle lights and colored lights also have impact when you layer several strands and pair them with ornaments having reflective surfaces.
To illuminate the tree from the inside out, string lights around the trunk and the branches. Starting at the base of the trunk and working up, wrap the lights around every major branch, moving from the trunk to the tip and back.
One year I decorated a tree in silver and purple. After wrapping lights around the trunk, I took big squares of purple cellophane, pinched the center to turn them into a cone (sort of) and stuck the pointy end into the tree. I did this all over, and the cellophane glowed from behind. Pretty cool if you like to change it up.
Don't skimp on lights! For every vertical foot of tree, use a strand of 100 lights.
And don't be afraid to mix and match lights. There's no rule stating that you can only use one kind. A "background" of white or clear lights can be highlighted with strands of colored lights that wrap the outside of the tree.
Try something a little different each year - and always watch after Christmas for the clearances on lights and decorations. I collect Shiny Brite ornaments from garage sales and flea markets.