How to place both ears symmetrically on the head???

I use a mirror and a camera, comparing the images constantly; I also use a tape measure. Maybe I've just been staring at the thing for too long, but they always look... "off", somehow. The ears themselves are perfectly symmetrical, but placement-wise, they aren't.

I'm considering taking a break and coming back to it tomorrow, because this is driving me absolutely insane. I've already torn one of the ears while removing it from the head (It was glued on), and have bent all of my small pins.

Any tips would be appreciated, thank you for your time.

(I'd post pictures, but the head looks terrible on-camera because I am inept at photography)