I love Zach Dell's two notebook idea.
"I'm the kind of person who needs to write clearly to think clearly."
Two different colored notebooks to distinguish when you're working in your business vs working on your business.
Working "in" the business (red notebook, at the office): Handling day-to-day operational problems and near-term issues.
"When I'm working in the business I'm blocking and tackling and solving problems that are blocking us today. I'm trying to figure out personnel problems and product problems and acute issues that are near term."
Working "on" the business (black notebook, at home after hours): Strategic thinking, planning 6–12 months out, war-gaming, and imagining big ideas.
"When I'm working on the business I'm thinking six months out, 12 months out, and kind of strategic war gaming and chess playing."
Zach deliberately segments his day: office hours for operational work, then time at home (after his wife goes to bed) with no phone or computer, just the black notebook for focused strategy: