When installing twinkle lights, remember that the best twinkles are natural and come from the light being blocked from view for a quick moment.
Concretely, this means that you should tuck your lights into bushes or Christmas trees or whatever (rather than onto), both to give more of a glow, and to increase the twinkles (if that's what you're into). Similarly, if you have a curtain of lights, you can put a sheer curtain in front, and the more layers/gathers, the stronger the effect of both glow and twinkle.
The opposite looks like this:
