The biggest gain for me came from using a split keyboard. I had some bad habits where my dominant hand was crossing the keyboard to hit keys that my non-dominan

The biggest gain for me came from using a split keyboard. I had some bad habits where my dominant hand was crossing the keyboard to hit keys that my non-dominant one should have been hitting, and this was impacting my speed. By using a split keyboard, it forced my hands in to the correct posture and didn't allow one hand to dominate because the other side of the keyboard was too far away. I was tracking my progress on typera.net, which is quite dated, but seems to have a nice balance of challenging words and phrases.