The antonyms for the phrase "more buttoned down" describe a person, behavior, or style that is less restrained, more relaxed, and individualistic. Expressive, flamboyant, and unconventional are some of the antonyms that come to mind. A person who is expressive is spontaneous, emotional, and open-minded. Flamboyant refers to a person or thing that is extravagant, showy, or attention-seeking. On the other hand, unconventional means breaking the norm, bending the rules, and daring to be different. These antonyms depict a person or lifestyle that is more free-spirited, creative, and unencumbered by social norms or expectations.