When I was a kid I wanted to be able to raise one eyebrow, but I couldn't figure out how. What I did was use my hand to raise it over and over again to kind of train the muscle. Eventually I could do it without the help of my hand! Also a fun fact: I only ever did it with my left eye brow for some reason, and now that's the only one I can move on it's own.
Interesting how everyone says they can only lift their left. I'm much better at lifting my right, but I'm also left handed. I wonder if they're related.
I did a similar thing to learn the Spock salute. Just wrapped an elastic band around my ring and pinkie fingers for two days to train my ring finger to be more independent from my middle finger.
Huh. I used to be able to do both (right better than left). Now I've got one of those notch scars in my left eyebrow just to the right of where that muscle pulls, and I can't get it to move properly. Fuck aging.