Finding synonyms for the phrase "feather in" can greatly enhance your writing, allowing you to add variety and creativity to your language. Some possible alternatives include "adding to," "boosting," "cementing," "improving," "strengthening," "enhancing," and "solidifying." Each of these phrases conveys the idea of something being added or strengthened, giving the impression of progress and success. Additionally, using a variety of synonyms can help avoid repetition and keep your language fresh and engaging. Take some time to explore different options to find the phrases that best fit your writing style and objectives.