Today, relevant usage of the word panache means:
a grand or flamboyant manner; verve; style; flair (Random House Dictionary)
Therefore, if you need to use the term in a sentence, you are probably talking about or describing someone who has noticeable style, presence and confidence. You may be commenting particularly about a distinctive flair for clothing style. You might be describing the way in which the person moves or acts, as they demonstrate energy and vivacity along with confident body language.
"Sasha was the admiration of all the party as he dashed in with charm energy and unmistakable panache."