Usually there is some sort of "feeling" or "sense" you'll experience. If you train yourself to be aware, you'll find that before you diss. your body had given you warning signals. I know when I'm stressed, I'll diss. so I try not to be stressed. One of my signs is scratching my palms w/ the same hand fingernails. Subtle, so I don't draw attention to myself but also if one knows, they would notice. Another is shaking my hand like I'm antsy. My husband & parents know to look for those signs & when they see them, to help me stay focused. If that doesn't work & I go anyways, at least they'll know. I had always told them to look at my eyes. If I have a glazed look, it means "I'm" not out anymore.
If you're comfortable w/ a person, you can maybe have them tell you what they saw before you diss.
Love,
RhysMadison