Time-boxing will improve your life.
At the core, it’s simple: assign a fixed period of time to a task, schedule it, and stick to it.
It works because it touches on so many aspects of behaviour:
The tricky bit is chunking the tasks and estimating how long they’ll take, but this skill improves rapidly with practice.
Key to this is time-boxing into a shared calendar and taking commutes, meetings, and other commitments into account.