Only working when I'm feeling alert and clear. I find it's far more productive over time to stop working every day as soon as I start having trouble concentrati

Only working when I'm feeling alert and clear. I find it's far more productive over time to stop working every day as soon as I start having trouble concentrating. I don't push myself to get in another few hours of work, I just stop. The second part of that is making sure I get a good full night of rest, so I can maximize the time I can concentrate per day. I realized that for many years I spent a lot of the time being groggy and sleep deprived. Only in the past few years have I learned to control my sleep and concentration.