What really helped me improve my typing speed is practicing to type daily.

When my fingers hurt after too much time on the keyboard, I like to take a short break. If I am writing an essay or something long, I usually like taking a 5 minute break to relax my fingers and give myself a short break to rethink my thoughts.

My tip to improve your typing speed is to get comfortable with the keyboard. If you become comfortable with the keyboard and its layout, you will have an easier time typing, and when it's easier to type, it's easier to become faster because you will naturally start going faster and faster.