Quite the opposite, as a matter of fact (and keep this in mind for when you find out who the winner is!)
I am paying so much attention to little details right now, that I forgot to mention something that is more important than all of the above. You have to listen to yourself & understand what impression you want to give. Now, it's not about being overly interested or dependant on what the others think of you, but in my mind it's ultimately about your psychological health. Yes, you heard it right: when/if it happened to me to be wearing something I didn't want to wear on a particular occasion, I felt almost sick. If you want to wear a skirt and you wind up wearing pants it makes you feel bad about your body. Your head sends indignant signals to your body. Mine does for sure.
So, in order to avoid precisely that, I had to include some other components into my 'dress for Tues night' formula.
The first part - weather - you've already seen. The second part - 'audience & ambience' was also briefly mentioned when I talked about how a girl's best friend is originality.
Going to a 5 star place with a 10 star person (oh yes, they do exist!) doesn't mean that you have to wear shiny stuff, especially if it's not the finest silks. The more you try to look expensive, the less you will succeed. But what works for me is turning the thing/situation on its head, putting on my slighly rebelious elegant air, mixing cheap & expensive, old & new & coming accross as what I am.
Weather (practical factor) = pants + Audience & Ambience (mix of practical & emotional)= relaxed sophisticated, casual with a twist