Help me not look like Inspecter Gadget when wearing a Trench Coat

[Chicinwellies]

So I have what I consider to be a very beautiful trench coat from Crew.
It fits well, has a belt, is lovely quality, but I feel like a twit wearing it. What goes with them, for everyday wear , and why does it feel so wrong !

I got a very nice, very cheap, tan/camel long-line (mid-calf) trench from New Look the other week. On me it works with casual clothes, but looks Go-Go-Gadget with smart things. Today I wore it with black ankle grazer skinny jeans and flat Chelsea boots and (I thought) it looked good, but it seems to morph into a flasher's mac with anything even vaguely formal. I also think that it's much, much better open than buttoned/belted, to the point that I've actually tied the belt at the back.

I don't button mine. I pull it together and cinch it with the belt which i knot and double back on itself IYSWIM?

Tying the belt back on itself, so it gathers the coat at the back leaving the front flapping open used to work for me.