Deadlines you actually believe

A deadline you set yourself and can move is not a deadline, and you know it. Deadlines that work have someone else in them: a supervisor expecting a draft on Tuesday, a study partner who will read it, a session you booked and would have to cancel to somebody's face.

Build one real external checkpoint into anything long. It does not need to be formal — "I will send you the first section on Friday" to one person is usually enough, because now not doing it costs something visible.