I was reading a book on mindfulness the other day. The author, who was also a manager, found she was always thinking of planning her next project when she wanted to be focusing on what she was doing. So she came up with a workable solution: she set aside time for planning. When she wasn't in this planning time, she would focus on what she was doing. When she was in the planning time, she focused on planning. Seems to me a good way to be efficient.