You will need scissors and a sewing machine, or access to one anyways. Keep in mind the length and width that your costume will need to be to fit the person who will be wearing it.
This homemade costume idea comes together by stenciling identical outlines on each piece of felt. Some ideas include
After this step the 2 pieces of felt are paired and sewn together (make sure to leave arm holes so that the person wearing the costume can move freely.
The next step involves painting lettering across the bottom such as what scent you are going to be or the name of a city etc. Finally you will fit the rope onto the top of the costume.
This rope acts as your hanger and can either be pinned on or you can cut a small hole in the top of the costume to string the rope through.