Mistress Kang,
I know that wearing a leather outfit, immediately comes to mind in concert with a Domme, but I share similar feelings to Footslave, I adore the schoolgirl outfit/look, you wear it so well, as I love a dominant woman coming from what might typically be an unexpected source, such as a schoolgirl, that excites me to actually see what a girl dressed in this manner is really capable of. I must say that my mind races everytime I view Schoolgirl 6.
As for a clown, I honestly think that you could actually make any outfit work, you seem to have a dominant presence that shines through, plus clowns can actually be pretty scary, as in the film Killer Clowns From Outer Space.