The term "down-at-the-heels" is used to describe someone or something that is shabby, worn, or in poor condition. Some antonyms for this phrase could include words like polished, refined, elegant, or classy. These words suggest a sense of sophistication and style, rather than a lack of care or maintenance. Other antonyms might include terms like new, pristine, tidy, or well-maintained, which indicate a sense of freshness and cleanliness. Regardless of the specific antonym used, the idea is to convey a sense of high quality or upkeep, as opposed to something that is run-down or neglected.