clad, dolled up, dressed, dressed to kill, dressed to the nines, spiffed up, spruced up, dress-suited, dress-shirted, full-dressed, more...

casual, dressed down, informal, relaxed

formal, black tie, white tie, cocktail, more...

was (for halloween),   decked up,   more gussied up,   formally attired,   suited up,   got all decked out,   dressed to impress,   all dolled up,   gussied (up),   formally dressed,   pressed up