Recognize the point of 'diminishing returns.' The above steps do not imply that you should work yourself to the point of exhaustion. You need to protect your health and the integrity of your job. Working yourself to a frazzle constantly makes you prone to mistakes. When you're so tired that you realize it's taking you twice or three times longer to do a job than normal, you need to call it a day. Rest at least a few hours and come back fresher, so that you can be strong at the end of the job. Learn how to power nap.