I do a lot of tour hosting and have a lot of memes between three sites, so for me, this calendar is invaluable. Each site (I have three) has a color and I set a reminder for each post for the day before so I don't forget. Now that I have an assistant to help me do more of my author stuff (and he takes care of some of my tour hosting posts), I have more time to focus on reviews and memes. And reading! I'm insane enough to be doing The Mad Reviewers' reading challenge this year, so I definitely need time for that.
On top of my calendar, I keep notes and makes lists. Lots and lots of lists. I write a lot of my "To-Do" stuff down in my notebook or make a list in my iPhone. I prioritize tasks by the most urgent or important and check them off as they're completed...well, most of the time. But the lists do help me keep myself on task. I'm easily distracted by things such as Pinterest and Netflix if my mind is left trying to figure out what to do next.
The days I work are the hardest to manage, that's why I manage my days off carefully. Every hour is precious and they are here and gone before you know it. I usually schedule the earlier part of my day for blogging and tour business. That way, when I start writing, I won't have to stop to take care of other things. Sometimes, however, my blogs take up my entire day. That's all right, because it keeps me from getting burnt out writing. If I get burnt out, the writer's block snags my ass with a vengeance and it takes forever to shake it off. I'd rather avoid it if I can.