What would happen if you made a 30/90 rule?
It looks like this.
For every “ten minute job” that isn’t completely routine – an email, a payment, a quick call – allow 30 minutes in your schedule.
Then you’ve got five minutes to be running slightly behind and get to the loo or make a coffee, ten minutes to find the email, password, bank details, and other incidental information you’ll need to do the job, ten minutes to do the actual job, and five minutes to be running late in, making coffee, firing off replies to short messages in before the next thing.
Allow 90 minutes for every one-hour meeting. If you really have an hour’s work to do (and you’ll probably lose focus if you have much more) and you want to do it with time to say hello properly to the person you’re working with, to actually think, and to finish on time, then you’ll need an hour and a half. Time to say it’s time to finish fifteen minutes before you do, time to note follow-up actions and book the next meeting, and time to actually finish and get out of the room.