The one, simple thing you can do to increase your productivity more than 10-fold is to learn how to touch type.
This isn’t just about improving your performance at the keyboard. It has to do with removing distractions and obstacles when coding. It’s about becoming one with the machine, translating the thoughts in your head into code, without having to hunt around for the right key and pressing it one at a time. Your brain works much faster than you can express your thoughts, and anything you can do to bridge that gap improves your performance.
And this has a multiplier effect as you learn how to use a good editor.