A goal is something you achieve. A commitment is someone you become. Turn one into the other.
Anything. Real or aspirational. "I want to run a 5K." "I want to write a novel." "I want to be in better shape." One sentence. Be specific.
A 5K is a goal. A runner is a commitment. Strip away the achievement — what kind of person regularly does this? The runner runs whether or not there's a 5K next month. That is who you are committing to become.
Three small specific things that person would do in the next seven days. Not the version of you that's already there — the version of you you're committing to. Each action should name a day, a number, or a person.
Aurelius's job: separate what's in your control from what isn't, and name any action vague enough that no one would notice if you did or didn't do it. The marble doesn't argue back. He does.
Print the card. Tape it where you'll see it Monday morning — bathroom mirror, fridge, laptop lid. The actions are small on purpose. The point isn't the action. The point is that the person you said you were becoming actually did them.
Reread this card in seven days. Did that person do those things? If yes — you are that person. If no — that's data, not failure. Edit the actions and run it again.