Heck, if I posted my list of possible cuts to look for (beyond superfluous characters or weak subplots), I sure can't find it. So here goes. I make no claim this is comprehensive. If anyone can add to what I've said, please do so. I'd love to trim sort more.
This is in addition to what has been said by me and others already about overdescribing actions (or anything else for that matter), unnecessary dialogue tags or actions, stating the obvious, redundancy, not using possible contractions, and wordy passive and progressive constructions. (And my em dash trick
) Everyone probably has phrases they overuse as well. (One of my worst offenders is "under the circumstances.")
Then there is the laborious process of examining everything slowly to see if it is (1) necessary and (2) stated in as few words as possible. Uncle Jim, in his wonderful threads on AW, says every line must do one or more of the following: support theme, establish character, or advance plot. I might add a fourth thing for my writing--bring a laugh (or, at least, a smile or eye roll).
very, really, just, rather, -ly (yeah, really's will be caught by this but I find it useful to do those separately), that, somewhat, quite, indeed, so, well, okay, oh, here, there, now, then, anyway, at all, sort of, still, sure
dialogue may be repetitious or unnecessarily have people addressing others by name
first person accounts may have "I (thought/saw/heard/knew) X" when I could simply say "X"
use of "began to," "started to," "could," "was able to" in cases where I could use the main verb by itself
