Is what trampy or fun? I don't really get the question. Here are a list of things I think could go either way...

Small straw cowboy hats: Trampy. In my circle, we call them "skunt hats" because they are generally worn while out skunting.

Knee-high boots: With big platforms-trampy, with the appropriate heel height, fun.

Backless shirts: When worn with the right undergarments-fun. When wearing a pink backless shirt with a black bra, trampy.

Cleavage: When shown appropriately, with appropriate support-sexy. When the shirt cuts down to your naval and you don't have on a bra-slutty.