Three things: learning one editor (Emacs) really well, learning new languages that force me to think differently, and as am6100 said, writing a lot of programs.
I went the other way this year and am now almost totally in Emacs. I recommend trying the vimpulse package for Emacs if you ever want to come back to the dark side.
Last week, on a whim, I went cold turkey to vim.
The result: I'm probably staying with a (heavily modded) vim.
I added the standard bash/emacs/OS X input keybindings to insertion mode.
It feels like the best of both worlds.
The moral: it's good to branch out and try new things every now and then. You might get surprised.