Slowing my pace is not a matter of just doing less. It's a matter of thinking less--or rather thinking of fewer things. Better yet, think of only one thing at a time. When I give my entire attention to what I'm doing in the moment, I'll not only be more effective, I'll be more focused and peaceful. I may even be in a flow state.
The only time I multi-task is when one of the tasks require no mental effort at all. I listen to podcasts while on the treadmill or while doing housework. I read spiritual books or do Sudoku puzzles while I eat. I only check email once every couple of days.