This is not what the word “modesty” means. Yes, it is what we mean when we churchify language, and I am sure that churchification gets it a tertiary definition in some dictionaries, but the word “modesty” means “not showing off.” You are a modest winner, you are gracious. You are a modest student, you don’t disclose grades. You are a modest philanthropist, you are anonymous. You are a modest person, you don’t brag about how much money you make. You are a modest teenager, you are not constantly blowing up everyone’s feed with selfies.
Don’t show off in general. The implications for dress from this are obvious and do not need to be overstated, as they represent a small part of modesty so understood.
That is modesty. There is also just generally being considerate of others, so, even if you have transcended beyond where you could ever show off, you still do not walk around naked. But that is not modesty, that is just trying to be considerate of others’ senses of propriety and others’ weaknesses, which is also a worthwhile virtue.
For me, that is all there is to modesty.