My tip to improve your typing speed is to...practice, practice, practice..... repetition works.

When my fingers hurt after too much time on the keyboard, I... try to direct my focus on my eye sight, because if I have spent enough time on the keyboard to make my fingers hurt, I know that my eyes must be straining to keep focused... and this can only end in one way....... a throbbing headache. FYI many short sessions is better than one long session any day.