How do get a very high speed???

My tip to improve your typing speed is to...

Continue to type as much as possible. If you find yourself lacking on a certain key, find some practice on that key. I personally do a little worse when I'm constantly shifting for the lower left side of my keyboard, and I'm working on that. After you know roughly what you're doing, practice without looking and build up via accuracy, and not speed. Remember that last part always.