Some people may have different lists and a different definition for filler words than I do, but these are the words that should be cut if possible. You'll notice that they're mostly used as adverbs. I call these empty adverbs.
quickly suddenly very really rather quite extremely fairly pretty ...etc.
These words fail to add anything to a sentence.
Gordon quickly scaled the very steep cliff. His water bottle was rather empty, leaving him extremely parched. The sun was really bright in his eyes, blinding him. It was quite difficult to see the handholds above. He wiped the sweat from his eyes, fairly sure he had a good hold on the rather slick rock. He was wrong. Suddenly, his fingers slipped, and he fell.
Now, take those filler words out.
Gordon scaled the steep cliff. His water bottle was empty, leaving him parched. The sun was bright in his eyes, blinding him. It was difficult to see the handholds above. He wiped the sweat from his eyes, sure he had a good hold on the slick rock. He was wrong. His fingers slipped, and he fell.
The second paragraph is punchier and it says the exact same thing as the first paragraph, and not only that, but I cut nine words.
Do you use filler words? Search your manuscript and cut them out. Your sentences will read stronger and get to the point faster, leaving room for details you might not have had space for before.
As always, there are exceptions. Having one of these words once every five-thousand words is okay. Having two-hundred, not so much. When I first started writing, I used more filler words than a Twinkie has lard. They're a subset of adverbs, the evil kind. Personally, I like adverbs. I use them a lot. But I make sure that the adverbs I use add something to the sentence as a whole, when the idea can't be expressed any other way.