Psychodrama
Role-playing, or pyschodrama as it is sometimes known, is one of my favorite activities. I consider this form of fantasy to be more of an addition to a session, then a stand alone activity. What I mean by this is role-playing usually is an adjunct to other forms of BDSM. Spanking on its own might seem boring, but giving a "role" for each person to play can make it exciting and thought-provoking. With this in mind, you can add an element of psychodrama to any scene. Instead of me acting as the Mistress and you the submissive, how about I play the Stepmother, and you the teenage stepson? Maybe you have had fantasies about that hot teacher whom you once had a crush on in school. Some other personas I have taken on for a session: baby-sitter, older sister, police officer, executive, doctor/nurse, secretary, slave owner, queen, Catwoman (or any heroine for that manner), etc. The possibilities are quite endless.
Of course, the ultimate in role-playing is when there are multiple parties involved. If you are feeling really daring, you can request another Mistress or Switch to add some additional realism to your scene. Two women can come up with endless ways to torment and torture you...