Michelle Styles:

I type too fast and not very well. I could blame the keyboard which is full of crumbs and dirt. Or it could be wearing out. I have heard of such things happening. Sometimes my keys even stick, or the space bar doesn't work when I think it has. But really it is all down to my terrible typing.

When I reread what I have typed, I see the words I think I have typed. Sometimes they are not there. Sometimes they are misspelled. But do I see them? NO! I go blithely through life thinking everything is fine, UNTIL that great moment and I reread and squirm. How could I have been that blind? How could I have done that? I know how to spell the or what.

I can see them (sometimes) if I go to another medium -- ie hard copy.
I can see them (often) when I read the work out loud. This is I do not do enough. I need to.

My old editor (aka the one who just left) pointed this out to me, gently. AFTER the fact. I have apologised. I do not like giving editors extra work. It is not their job. It means they have to spend a longer time on my manuscript. (Luckily occasionally I do write a good story.)
My new editor (aka my first editor) will not put up with it. She will point it out during revisions. I need to make sure that piles of wool do not turn into peas. I need to make sure the motivation is on the page instead of in my head. I dislike giving her more work. Honestly I do.
BUT mainly I need to make sure that I turn in clean copy with a Good Story.
I am a terrible typist but there are ways in which I can improve. I will try. Truly.
The wip is in its final stages and these things become important.