Originally Posted by Cantabrigian
You're answering the simpler and less interesting question.
What you wear for formal and CBD occasions is fairly apparent.
We're talking here about how you evaluate an outfit when you could otherwise wear shorts and a tshirt.
On that point, you seem to be in the camp that items have a set or at least largely determined level of formality. I'm not sure I agree (or disagree for that matter) but I'd like to hear more about why you think that.
It's tough to articulate exactly "why" I think this way re: items having a determined level / range of formality; it just seems intuitive. I may be talking in circles a bit here and feel free to try to drill down on anything further, but let me give some examples of how I'm thinking about this. Level 1 (formalwear) and Level 2 (CBD or otherwise business formal if not fully CBD) are pretty obvious, I agree. Maybe you dress down a worsted solid suit by pairing it with a BD collar shirt (not a fan myself but at least IMO it's not awful) or wear a more casual tie with it but that's about it. The conservative worsted suit with no tie look to me is an instant fail and just looks stupid IMO. Level 1 and Level 2 are pretty boring as I think that formalwear and conservative suits have very limited range.
Things get more interesting at Level 3 through Level 5 (there is probably a Level 6 too if we go casual enough too). A casual look built around jeans, for example, can be spruced up by a nice pair of loafers, monks or derbys in place of the awful athletic shoes that get worn way too often (oxfords say business formal to me and are jarring to my eyes with jeans). I'm not sure if it makes the look much more formal (I think the denim dominates the formality discussion no matter what you do with it) but it probably gives it a more sophisticated appearance at the very least. Wear jeans with a jacket and tie and it just looks wrong, like the top and bottom half of your body is engaged in some sort of schizophrenic battle. Just like denim dominates the formality discussion, I think the sockless look calls attention to itself and singles out an outfit as casual. In both cases, wearing a tie is a complete syntax fail (the fact that the sockless look in this thread involves double monks makes it that much worse as I really only think the sockless look works with something as effortless as a slip-on shoe, not even going to touch the way too short pants). You have something that is jarring because when one item suggests very casual and the rest of the outfit suggests something much more formal. Try the sockless look on a lazy summer afternoon when you're wearing linen trousers / shirt / summer odd jacket sans tie and it works because jacket sans tie is not so inherently formal as to creating a jarring contrast. I think the key to playing with the formality level of your outfit is to make more subtle changes.
A good example of a garment with a wide range of use (at least in the U.S.) is the navy blazer and its contrast with other odd jackets. Pair it with black shoes, medium grey trousers, white shirt and a conservative solid tie and it's just a small step down from a suit in terms of formality. Try this with any other odd jacket; it just doesn't work as there is a limit to how formal you can possibly make something like tweed or similar jackets look. Substitute the white shirt for a blue shirt, the grey trousers for tan trousers and adjust the tie accordingly and the navy blazer gets dressed down to the "California Tux." Most other odd jackets can play in this environment now too. Now take off the tie. I think this is the utter limit to how much you can dress down the navy blazer and some other odd jackets. Some tweeds might work with jeans and a dress shirt. I think the navy blazer, which can be stretched reasonably high in terms of formality just looks completely out of place here. A casual odd jacket can still work. Switch out the dress shirt for a t-shirt and you're done with odd jacket land; an odd jacket in this context just looks dumb IMO. I could maybe see a casual odd jacket it with a nice sweater serving in more of an outwerwear function, but that's it. To a lesser extent, maybe a linen odd jacket with something like a polo. I'm not recommending these looks; just saying that's as far as I can see one going without the contrast in formality being too jarring.
So most casual looks can be spruced up, even if it does not really make them more formal, with a nice pair of shoes that is not a pair of oxfords. Going sockless can make a casual to business casual look a bit more relaxed and casual when done in the summer and with loafers. Some odd jackets can dress up a casual look and most odd jackets can be dressed up or down by adding or subtracting a tie or switching up the trousers. In any event, each garment has their limit to how formal or how casual you can make it. Subtlety is key in adjusting the message a particular garment sends.