I just took one, right before writing this. I came back with a level head and was ready to roll. It’s very important to stop what you’re doing once in a while and hit Refresh. You can read that advice anywhere, but do you actually follow it? Make yourself do it. It will pay off.
Take a walk. Run an errand. Pull some weeds from the garden. Look at shoes or fishing rods or toasters online. Do some jumping jacks. Stop for coffee somewhere–not because you don’t have coffee where you work, but just to put yourself in a different environment. Chat with someone. Soak in the sunshine. Smile.
This does not take time away from your work. It actually helps your work, because you return to it with a clearer head. Everything actually goes faster when you take appropriate breaks. It’s like the French Paradox. where you eat more but don’t gain weight. Take more breaks and you will get more done.