Most of my errors are leaving in or missing out words during editing, rather than spelling words wrongly. I have decided the way to make my work better is to get somebody else to proof read it. In a conference paper I recently wrote it came out with "pennycook" written at the end of one of the sections - that's part of one of my bibliography item labels, and I'm sure readers would have figured that out, but it still looked silly.

(Pennycook is the name of somebody who is very important in the field I'm writing about, who may well be at the conference the paper was for!)