Stylish — describes something fashionable, sleek, or well-designed. Used for clothing, design, behavior, etc.; usually written in katakana.
彼はいつもスタイリッシュな服を着ている。
He always wears stylish clothes.
このカフェは内装がスタイリッシュで落ち着くね。
This café has a stylish interior and feels relaxing.
スタイリッシュに見せるコツはシンプルさを保つことだ。
The key to looking stylish is keeping things simple.