This is a great question. My own motto (stolen from Wil Wheaton of course) is "Don't be a dick", so whenever I learn that my words are offensive, I start using better words.

But, I am no angel. I just learned yesterday that I've been saying something constantly for my whole life that is offensive to the disabled- it's simply the word "Duh". It comes out super automatically anytime I do something dumb. I don't mean it to be unkind to anyone with a disability- I am autistic myself- but I'm going to have to work really hard to stop using that one.