An oldie but goodie from Paul Graham: Maker’s Schedule, Manager’s Schedule.
Posting this as a personal bookmark because it comes up often in conversations with new leads. When I talk to people new to management I highlight the mindset change from “just you” to “the team.” The context of an outward mindset is important — you don’t own your time when you manage more than your own time. Keeping track of everything changes drastically when you start paying attention to more that just your own time and tasks.
This explains the frustration of a work day gets cut short — which can happen if something comes up unexpectedly or you’re continually interrupted. The resulting “short period” of time for making or creating is essentially lost. The big project, like the essay or talk you need to start on, don’t get attention because you don’t have the time for deep work.
Another clue for discovering the maker-vs-manager mindset is how you view your calendar. By month — and not by week or day — means you could be in maker mode. If you care more about every hour or 15-minute interval, you’re likely in manager mode.
A visual note to illustrate this concept:

Meetings can be disruptive to makers, says @phil_wade on Twitter. This ties into the concept of “flow state” made famous by Mihaly Csikszentmihalyi and others. If you’re curious to learn more, search that name (hard to spell!) for his talks and books — and read my thoughts on the flow fallacy.