Some more, somewhat random, suggestions:
Head accessory: Head band
Various options could be available as I expect a plain one would not add much to the game.
Animal ears - rabbit, dog, cat
Misc - stars, moons, suns
More of a cute instead of lewd clothing option.
Under outfit: Leotard
Uses both the bra and panties slots.
More or less skin tight - think along the lines of a bunny girl leotard.
Embarrassing to be seen in (treated as underwear) but less so then nudity and takes longer to put on or remove (increased risk of getting caught if you pick a bad - or good depending on perspective - time to change into or out of it)