I think any tips I'd give to typists seeking to type faster are:
-Type in blocks. Some days, type with only accuracy while others go for speed. This will build up your skill and combine both accuracy and speed to slowly get better at typing (or at least, that's how I did it!)
-If you haven't already, MEMORIZE YOUR KEYBOARD. I recommend a keyboard displayed on screen so you get used to not looking down at your fingers.
-If you get stuck in "blocks" where you can't get any faster, take a break for a week and come back to it. I've done this before and have grown by a whole 10 WPM!