I disagree with ILbob's first point and agree with his second.

Wood grows in all sizes in nature. There is some thought that you can split dry kindling from the center of a larger piece when everything is wet, but if you have good, long burning tinder you don't need to.

On the second point, you're dead-on. Start at the top of a long dead tree and work your way down to the thick end, burning as you go.