Take a shower.
That's what works for me when I'm lagging behind in the day.
"Everyone who has ever taken a shower has had an idea. It's the person who gets out of the shower, dries off, and does something about it that makes a difference."
- Nolan Bushnell
And for some inspiring reading, here's a Warrior of the Light article written by one of my favorite authors, Paulo Coelho. :)