Pat Holt, former Book Review Critic for the San Francisco Chronicle, has a good piece on his Web site titled, Ten Mistakes Writers Don't See (But Can Easily Fix When They Do). Many of the tips apply to authors writing fiction, such as tips on describing scenes and recommended use of dialog. But there are numerous good tips for non-fiction writers as well.
One of the ones I identified with was Mistake #1, Repeats:
Just about every writer unconsciously leans on a "crutch" word. Hillary Clinton's repeated word is "eager" (can you believe it? the committee that wrote "Living History" should be ashamed). Cosmopolitan magazine editor Kate White uses "quickly" over a dozen times in "A Body To Die For." Jack Kerouac's crutch word in "On the Road" is "sad," sometimes doubly so - "sad, sad." Ann Packer's in "The Dive from Clausen's Pier" is "weird."
Crutch words are usually unremarkable. That's why they slip under editorial radar - they're not even worth repeating, but there you have it, pop, pop, pop, up they come. Readers, however, notice them, get irked by them and are eventually distracted by them, and down goes your book, never to be opened again.
I have some crutch phrases I find popping into my articles and books. For example, I often follow potentially complex statements frought with technical jargon with a sentence starting: “That is,” followed by a simpler explanation in everyday English. I like to pepper my writing with many examples, but have trouble finding verbage to use other than, “For example,” to start an example. (See the second sentence in this paragraph for a prime example......) I also seem to be fixated on starting sentences with, “Realize that...”