You should wear something that makes you look pretty.
You should come in an attire that makes you look your best.
ーYou should wear something that makes you look pretty.
「あなたが可愛く見える服を着てきてね」
to wear something that makes you look pretty で「あなたが可愛く見える服を着る」
ーYou should come in an attire that makes you look your best.
「あなたが一番素敵に見える格好で来てね」
to come in an attire that makes you look your best で「あなたが一番素敵に見える格好・服装で来る」
ご参考まで！
カナダ 
