It's sometimes annoying how poorly I type. I took typing in high school, but I didn't practice enough to realize the benefits. So I still only use five fingers to type. Funny thing is, people are sometimes impressed when they see me type. My fingers fly around the keyboard (they have to, since I only use 5 of them), and sometimes I can get on a roll that does look rather impressive. But that's only until you check my accuracy.
My most common errors are transposing two characters. I type "coudl" far more than "could" on the first try. "Woudl" and "shoudl" are also very frequent typos. Sometimes, I'll get out of synch and type a word with two or three consecutive transposition errors. That probably tells me something about either the mechanics of how I press the keys, or how my brain tells my fingers to press them. When I'm independently wealthy, I'll commission a study on myself.
At least these errors almost always produce non-words, so as long as I spell-check my text, they are caught and corrected. This blog, however, does not have a spell-check built-in, so unless I catch my mistake, you might see an occasional error slip by.