My tip to improve your typing speed is to... keep the mistakes you make in mind before you start and then clear your mind as you type. If you think too much about where your fingers are going you're going to try to look down and then you slow down. Just clear and go!

When my fingers hurt after too much time on the keyboard, I... stretch them backward by placing the pads of my fingertips on the edge of the desk and pushing down and through. Gives a nice full hand stretch!