We agreed that a lot of what we then considered "working hard" was actually "freaking out". Freaking out included panicking, working on things just to be working on something, not knowing what we were doing, fearing failure, worrying about things we needn't have worried about, thinking about fund raising rather than product building, building too many features, getting distracted by competitors, being at the office since just being there seemed productive even if it wasn't -- and other time-consuming activities. This time around we have eliminated a lot of freaking out time. We seem to be working less hard this time, even making it home in time for dinner.
I would likely give the same advice, but I wonder if it's actually true. Perhaps working hard/freaking out was exactly what was needed at the time, whether or not it seems efficient or correct in retrospect. You need to travel that road so you can find a better way the second time around.