Most workdays contain transitions in name only. One call ends and another document opens before the body has registered that anything changed.
At the end of a task, close what belongs to it. Place both feet on the floor. Look at the farthest object you can see, then take one breath whose exhale is slightly longer than its inhale.
Name the next thing once
Say the next task in a short sentence: now I am writing the opening paragraph; now I am making lunch. The sentence gives attention a boundary without turning the day into theater.
A transition is not wasted time. It is how the mind learns where one demand ends.
Ninety seconds will not repair an impossible workload. It can, however, prevent one task from carrying its weather into every room that follows.