With a question such as this one, you'll need to recognize that, unless you can read Ancient Greek and have the Homeric original, you will be working with a translation, and as there have been numerous translations of The Odyssey over the years, this means that the answer to this question will be shaped by which translation you happen to be using. For this answer, I am drawing on the Robert Fagles translation, published by Penguin Classics in 1996. This translation is rich in its use of epithets and poetic turns of phrasing.
Perhaps the most notable epithet used in this version, in reference to Circe, is her identification as "the nymph with lovely braids." Additionally, you can observe her being referred to as "Circe skilled in spells." (On page 239, you'll find the following words: "I was nearing the halls of Circe skilled in spells, approaching her palace"). She is also is given the adjective "lustrous."
One thing that is interesting, and worth being aware of, is the degree to which these epithets can be reused across The Odyssey, in reference to different characters. You can see this with Calypso, who is also given the adjective "lustrous" and referred to within the poem as "the nymph with lovely braids." Epithets form a core part of The Odyssey's poetic language (a factor which should not be surprising, given its origins as part of the oral tradition, requiring memorization and recitation).