Guess I'll jump into this thread since it is a topic that actually interests me (translation: I spend entirely too much time in the tailor screens.)
This is my main Science captain and her two main uniform choices. The left is a dress uniform concept I've been playing around with (I'm aware of the diplomatic uniforms from the TNG films, I'm just looking to see what I can come up with) and the right is her standard duty uniform.
The crew uniforms, left to right. Science, Medical, Operations/Security, and Command. Only difference between captain's command uniform and the subordinates is the belt.
As for my main KDF type, I unlocked the Elite Commander version of the Honour Guard a long time ago and fell in love with it then, it has become my uniform of choice. That said, I tried to come up with something a bit dressier/showing off decorations and such and the right is that.