Historical, fantasy, magic, horror, supernatural, survival, vampires, demons, pirates, mutants, ghosts, romance (FxF, MxM, MxF) (Romance should be part of the plot and not the whole plot in itself), etc.
There are many ways you can advertise your roleplays. If it is a group roleplay, then you can create a banner (or ask someone to help you create a banner if you don't know how to do it. You can make a request in the art museum's request section) and send it in to be put into the ad rotation.
You can also post a thread in the roleplay advertisement section. Explain what your rp is about and give a link to the sign up thread.
The blogs are also a good way to make people notice a roleplay, and that can be used for both one x one and group roleplays.
Lastly you can also tell people about your roleplay on your profile. Even if other people writes on your profile after that, your personal post will still be visible at the top and when people click on your username until the day you make a new post.