Writing advice often relates to the same two topics: show, don't tell and write in the active voice. So, say you're taking on these two nuggets of wisdom. You're ready to incorporate the advice you keep getting from your critique partner(s) and your writing group! You've learned everything you need to know about how to change passive voice into active voice and how to show rather than tell. Yet, even though you've made certain to use verbs that aren't being verbs and you've incorporated adjectives as descriptors, your writing still feels clunky. It's still getting dinged at your critique group meetings.
This is because oops! in trying to fix one problem, you've introduced a new problem. And that's the use of filter words and filter phrases in your writing.