Look after your soap and it will look after you. To get the best out of your soap and to ensure it lasts, it's important to make sure it dries out after each use. If it sits in a wet soap dish it will go mushy underneath and won't last so long.

Use a small soap dish so that the soap can sit at an angle rather than flat on the bottom of the dish.  That way it will dry out between uses and will last much longer.