I have made much more progress than I anticipated in just 4 weeks. I now regularly type at 50-55 words per minute, and sometimes hit 65. This is learning a new keyboard layout in addition to learning touch typing. I have for typed exclusively in Colemak for at least two weeks, and find that my old QWERTY muscle memory very rarely interferes. The S, which was one of the hardest transitions since it only moved one key over, is second nature now. Of course, I still make many mistakes. And interestingly, I cannot type well when tired. The new muscle memory hasn’t gone that deep yet.
I have noticed that I do my fastest practices early in the morning, and on the first try. The following tries are inevitably slower. I suspect it is because I attempt (against my conscious will) to type faster than my hands have learned in the succeeding tries, but there is no such impulse in the first try.
The most important thing I have learned is the need to keep your fingers on the keyboard. I previously typed by looking at the keys because I floated my hands above keyboard and needed to realign often. But by keeping most fingers where they need to be, I hardly ever lose the keys. That’s the one trick I’d recommend a beginner touch-typist to focus on for fastest improvement.