They say my smile seems nervous and fake, how can I fix this?

I'd have to agree with Mary Lynch's answer, the more you focus on it the more odd your smile will appear. In terms of some actual advice as well, one way to determine when someone is genuinely smiling or simply smiling to be polite is when they have crow's feet around their eyes. Like this. read more

I think the more you try to “fix” what others perceive as a fake smile, the worse you’ll make the problem. Try not to think about your smile, as self-consciousness impedes your ability to register natural, spontaneous emotion. read more