I generally pick a goal for the day, and then work hard towards it. If I've done it right, I don't have the energy to start another big rock mid day. Best I c

I generally pick a goal for the day, and then work hard towards it. If I've done it right, I don't have the energy to start another big rock mid day. Best I can do is think about what tomorrow's big rock is going to be, and get myself set up to hit the ground running. That feeling of never-ending work (and thus, work until your brain is toast) is anathema to being maximally productive. It just makes me take longer on each day's big rock so I'm not burning myself out in the long term anyway.