Flashing light strings are always a big hit on Christmas trees and projects.
An easy way to add twinkle, the solution may already be in the little cellophane envelope that came with your set of mini lights!
In addition to an extra bulb, you might have a red tipped bulb!
Install it anywhere in the light string and after the bulbs warm up for a minute, the entire string will flash on and off!
Mix a flashing string with several steady-on strings to add "light texture" to your Christmas tree.