Idea #1: The Tomboy Princess
including such themes as crossdressing and bondage
I would venture to say this is one of the stranger ideas I've had in my time. Far from being something negative, though, strange is the fuel that keeps me going.
The basic premise is this: in a fantasy kingdom are a Prince and a Princess. A maid tends to both their rooms - not exactly a problem, since the Prince is generally away, learning swordplay and the ways of leadership. The Princess, meanwhile, has all the time she could want to wander the castle and learn its secrets. One such secret, overheard from a pair of servants, is that the maid who tends to their rooms enjoys occasionally dressing up in the Prince's clothes. The Princess chooses to confront the maid, catching her in the Prince's room as she's dressing up. From this point, there are several ways it could go: the Princess could join in, with the two of them finding it mutually exciting. Or the Princess could be excited by the maid-dressed-as-a-Prince. Or the Princess can be replaced with the Prince, in the same situations. Bondage and D/s is likely to be involved, with either character able to fill either role.
Idea #2: The Instructor's Lessons
including such themes as D/s, bondage and mild ageplay
In a medieval kingdom - or a science fiction one akin to Dune ( this would probably make me love you forever and ever ) - the son of a noble family is receiving instruction in swordplay by an exceptionally talented teacher, a woman a few years his elder. On the surface, she is a hard sort, not exactly given to romance.
Through rumor or other means, the noble son eventually learns that she, in fact, fancies him, but is far less talented in ways of the heart than the sword, and hasn't been able to work up the courage to in any way let him know. And why should she? He is, after all, nobility, and far outside her reach. What is more, though, is he hears rumors that she may not be the typical lover. Though nobody knows where those rumors come from, there are many who say she appreciates a firm hand and subservience, perhaps even physical pain, to simple lovemaking.
The noble son, suffice it to say, sets out to test those claims.
Idea #3: A Trap for a Thief
including such themes as D/s and bondage
During a storm, a traveling woman seeks shelter at an old estate along the road. She arrives in the middle of the night, knocking, pleading for a place to stay. The slightly eccentric, but well-mannered and handsome owner of the house lets her in, as any gentleman would, and lets her have a bed.
Far from her arrival being a coincidence, the young woman actually makes her living by conning unsuspecting men and women into sheltering her or taking her along during their travels, and then steals from and robs them. In this case, however, her plans are foiled by sudden illness. She wakes up the next morning feeling weak, after a night haunted by nightmares. Later that day, while she lies in bed still, the owner comes to check on her, to care for her and so on. A brief romance may or may not ensue.
Regardless, she's determined to rob him and move on a few days later. During the night, she tries to sneak off. In the process of escaping, however, she is caught by the master of the house, who turns out not to be entirely human after all, but rather a vampire.