You have to be better than you were at 25 (more productive, making fewer mistakes, able to take on greater responsibilities). You have to be better than you were at 30.

You don't have to be as actively sought after. You should be staying at positions longer - 5 years, maybe even 10. (Note well, however: By this point, you probably have seen several toxic environments. If you're in one, don't wait - get out. Life is too short to put up with it.)

I have a file where I keep track of headhunters that I think are worth their salt. I'll use it if and when I feel like it's time to move on.

For the record, I'm 55.