The personality that one has during the roleplay is an interesting display of acting style and ability in the sexual arts. It’s always interesting to see what role and behavior one takes in different situations.
There are two main considerations, first the environmnent and identity, the background. It can be fun to adobt stereotypical mannerisms, even accents, from British spies to Italian mobsters, from a Southern belle maid to a wild raver Berlin stripper.
Second, consider the motivation in the scene, in particular, how and why the situation turns sexual. In a bdsm scene, this one is typically easy as one option is just considering the Top is twistedly perverted and wants to hurt and use the bottom for his pleasure. In a strictly punishment scene for a transgression at, e.g., an office or a school, the willingness of the bottom to do “anything” to avoid getting kicked out of the institution serves as a useful clliche.
The Top may then play with the level of which he starts more timidly and then get hopelessly excited and enraged to attack and ravish, or, whether the scene is clear steady speed ahead, the Top relatively cold and emotionless, through.
The bottom may choose to be somewhere on the scale between docile and obstinate, or bratty. Docile subs can then be fun for the top to make commands they can’t fulfill so as to punish them. They tend to float in subspace much of the time, and the autonomous reaction of complete servility comes out in a nice connection. Bratty subs can add plenty fun to a scene, first by sassy wit, and second by the providing of the moment for the Top to show sudden complete dissatisfaction and a brutal conviction towards instilling authority.
In a more vanilla scene, say a masseuse or a poolboy, it becomes a nice dance of developing a convincing and still scintillating play of we shouldn’t, we should, we shouldn’t, we should, and who is more reticent and by how much. Accidentally smell, brush your hand across, etc. a place one shouldn’t, and then get excited and turn animalistically out of control, then stop and hold back and express hesitation again.