Josh Kaufman describes this well in The Personal MBA:
If you’re trying to create something, the worst thing you can possibly do is to try to fit creative tasks in between administrative tasks — context switching will kill your productivity. The “Maker’s Schedule” consists of large blocks of uninterrupted time; the “Manager’s Schedule” is broken up into many small chunks for meetings. Both schedules serve different purposes — just don’t try to combine them if your goal is to get useful work done.
When he says “don’t try to combine them,” he means, “don’t try to do them at the same time.” Most of us have things to make and things to manage (and wouldn’t want it any other way), and Kaufman gives a good model of how to integrate both into your day without creating interference between them:
I typically focus on writing for a few uninterrupted hours in the morning, then batch my calls and meetings in the afternoon. As a result, I can focus on both responsibilities with my full attention.
That’s a good approach: a large chunk of time for creative tasks in the morning, with the mid-day and afternoon free for those things that require dividing your time into smaller chunks and going with the flow.