Had never thought of this. Now I'm thinking about it.
My current dog is about 11 yrs old. Best dog I've ever owned. 85 lbs of teeth and fur. Among other things, I've trained him better than any other dog I've owned- he won't eat food -even if it's in reach, unless it's his food. He also knows how to crawl. I trained him to walk on his tiptoes- silently- when I want him to sneak up on a rat or other rodent. He will back up on command, and of course, sit and stay.
Wish I could get him to howl on command. Only does it when ambulance or fire engines drive by.
What are some things you taught or want to teach your dog?