Back when I was a student, I used to timeblock to get on with particular projects, whether it be that essay due in a fortnight, or a promise to make a dent in the reading list. I found this necessary because I realized that I had made it a habit to prioritize other people's needs over my own workload - agreeing to that rehearsal there, that committee meeting here - leaving me with unsociable hours to get my work done in. Timeblocking meant that when consulting my diary I was able to say 'whoops, sorry, can't make that time', and we'd find a different one.
I'd forgotten that habit until I read this article in the Independent by Zlata Rodionova. What Rodionova is suggesting is, of course, a little different: schedule time for yourself, just to think.
I'd add that you should schedule time every week for long term projects, rather than prioritize the immediately gratifying ones. Think white papers rather than answering emails, writing a book rather than a tweet, etc. Scheduling time for yourself just to think will help you work out which of these long term projects you would benefit the most from seeing through too.
Go and revisit your calendar, if it's full of appointments, consider adding a few more with yourself.