Too old now, but I once made a my own mask using an old gas mask (I wear glasses and it allowed me to do so) and a fright wig and had a friend make my a full length cloak. My first trip to a bar with it, I parked and headed to the basement bar when around the corner came three guys dressed as the ghostbusters. One of them yelled "there he is!" and I led them down into the bar and they chased me around the island seating a couple of times. Good times.
Another costume idea was I had a fedora that I wore with a dark suit and white tie. Went as a Mafioso. (Got lucky that night) ;)