Imprecise words can clog up your prose. In my original submission of Mojo Queen I used the word "finally" 27 times (I went back and used find and highlight to count). I just got the second round of edits for MQ and I think my editor has found all 27 times between these two round of edits and, er, suggested I fix them. So I did, because she's right. Why be so vague when I can either give a more precise indication of time, or cut the word completely?
Crafting sentences that belong in the Department of Redundancy Department is also something to look out for. I have a problem with this, especially in first person POV as Mojo Queen is. Here's an example: I used the phrase "risky danger" in narrative. Have you seen A Few Good Men? Remember the "grave danger" exchange, with Jack Nicholson saying, "is there any other kind?" That's what went through my head upon seeing that phrase highlighted by my editor. ;-) I cut "risky." Keep in mind, this was in narrative. I would have kept it if it had been dialog, as long as it was true to the character's way of speaking.
Don't be afraid to alter your darlings, either. Sometimes you might need to rearrange a sentence for clarity. Other times you might find you've used the same word three times in a paragraph. Unless it's some kind of specialized word and there's no way around using it so many times, you'll want to look at alternatives.
Sometimes you even have to trunk your darlings when a scene doesn't work out. But NEVER delete those trunked scenes or stories. Tuck them away in their own file and keep them, because you never know when you might want to cannibalize from them. I have a hard time with opening scenes, so I've scrapped five or six scenes in the last two weeks because they weren't strong enough. I have them saved and may be able to use parts of them later.
Killing, altering, and trunking your darlings is sometimes necessary, but I think you'll find