Some admin or planning tasks take far more time and effort than others (like those ones done in Tip 2). Schedule a time for these tasks when you know you have a fair amount of time to really get into it.
Also find a spot where distractions will be limited. If you work best at school, find a spot where no one can find you. If your fellow colleagues are expert hide-and-seekers, sit at your local Starbucks. If you have had your fair share of caffeine for the day, position yourself in your living room at home (or lock yourself in the bathroom if there are kids around).
If you are like me, I also tend to work better in the morning, rather at night. So mornings would be my most mentally productive times.
It doesn't matter where you are, just find a space where you can focus for the given amount of time and tackle the task at hand.