I went on a couple long walks with my wife, running in the middle of some of the walks, and on one I ended up with a blister on the bottom of my foot. It was a long, thin one that was more annoying then painful. I kept running with it across days, and it ended up coming off after about a week, just a patch of dead, dry skin.
It was still annoying after that, a reminder, and I tried to be more careful with my feet.
However I wasn't. A few weeks later I took the wrong shoes on a long trip. Not running shoes, just casual shoes that were loose and ended up rubbing a spot on the outside of my foot, next to my little toe. It got a little raw, and a blister there as well. That one was more painful, and more annoying while both walking and running.
In both of these cases, I didn't do much. Things weren't painful enough, or annoying enough for me to pad them, and I just ran with the irritation.
Not sure that was the best approach, but I also didn't quit, which is something I'd have probably done before this streak. Pushing yourself a little is good, and I've ended up being glad I did so over the last three years.