I would timeblock the scheduled meetings if I have a good idea how long it would go for, and if it goes on for longer than that, I'd move the next task for later in the day or the next day. For that, I also recommend scheduling some buffer time every evening to catch up with things that didn't go according to the plan!

And for improptu meetings, I'd try to NOT have impromptu meetings in the first place-unless urgent--and If I do have them, again, I'd reschedule the scheduled task for later in the day!

When we timeblock, it's not perfection we're looking for, just a little more clarity and purpose for our day ahead!