As I gain more experience I've found that stress comes in three forms; stress that is there that you don't see, stress that you recognize but still don't seem to manage, and on rare occasion when you see the stress and manage to change your behavior to fix it. For the most part I'm able to recognize what causes me stress, and in a lot of cases it's how rested & focused I am that determines whether I fix or live with it.
Even when I'm oblivious (on purpose or not if that makes sense) to the building stress, there's always one signal that I can count on to recognize that I'm oversomething, and that is my todo list growing against pending deadlines - which in turn triggers in me "work harder". Even when work iharder consists of putting in place some efficiency that will help me later, it's the danger zone. More work leads to more stress or at least more tired, things take longer, the cycle grows. The exception is when you can clearly define it as "if I can x, y, and z done then I'm back to normal...and...I can see that happening in 7-10 days max". I suppose you could draft more rules on top of that, one perhaps being that this only applies if you haven't done this in the last x days, but that's not important. What is important that due to email, client visits, lack of ruthless focus, illness, over committing - whatever the reason and they happen, you're jammed up and thinking to just work harder.
In most cases working harder is the wrong answer, what I call the death spiral. Instead, you go back to basics and prioritize...ruthlessly. Usually some of those have to have things don't really have to be done, and others can just wait a little longer. But it's not as easy as saying you'll just work 40 hours and go home, I wish it was! Sometimes it means closing the door and putting the head phones on, going all out or a few days to hit max productivity.
The other part - and the hardest lesson to learn - is that when you can't seem to get caught up, it's time to take a break. It's tough love, and doesn't sound like common sense, but we make bad decisions when tired and stressed. I wouldn't take this advice 10 years ago, and sometimes I still don't, but more often I do and it does help.
Think about that, and tomorrow we'll talk about it from a management perspective.