Dumb things I've done / Know when to quit.

When you're in the middle of a long project using power tools and it's getting near the end of the day and you're tired from working all day and you have a thought "I'll just cut one more board quickly (even if it is a tricky cut) and then we can quit for the day".

Stop while you're ahead!

Don't turn on the table saw!

Spend the rest of your energy cleaning the job site or reading the safety manual for the saw instead. Have a cold beverage. Read your email. Comb your hair. Just stand there and look at your shoes. Do anything but turn on the saw!