What really helped me improve my typing speed is... I practiced for 8 - 12 hours a day. I use the fingers that I'm comfortable with to hit the appropriate keys, but I also use the touch-typing method, however, I usually use 9 or 8 fingers while you need to use all 10. Using shift to use capital letters are fine, but using Caps lock is also good. Use an external/normal computer keyboard, small, and laptop keyboards are less effective and lowers down your speed. You also do mistakes usually. I also use a mechanical keyboard, so think about buying one (most are around $100 - 150). They have special switches under the keys and have a loud "clicky" sound. They also feel much comfortable than normal keyboards do. Practice a lot, and you'll get much faster.