Judo tips, part I

When you're doing 寝技(matwork), be sure to keep your weight on the bottom of your feet, where it's supposed to be. It's not that you should be crouching, but be sure to keep your toes under you when you kneel. By doing this, you provide yourself with better power, and help to prevent the following from happening:

That's from... yesterday, if I'm getting my days right. I didn't realize how deep of a matburn I had on my feet, and I didn't disinfect it. You can see the results on my left (top) foot with the yellow coloration on the scab tissue.
So. The lesson here is:

Don't use your feet upside-down.
And if you do, fix 'em.