Better And Better: Let me have your take on this:.
When is a suit mandatory for a man to wear?
When is a dress shirt and tie mandatory?
When are tennis shoes out of the question?
When are walking shorts out of the question?
You opinon on caps and hats?
Collared shirts (golf shirts, polo shirts) versus T-shirts?
Tucked shirt vs. untucked?
And finally, buttoned-down collars on dress-shirts vs. non-buttoned-down collars?
I'm not sure I can really answer these questions. After 13 years in the Army I seemed to have lost the ability to know how to dress for what occasion. Because for 13 years I was told exactly what to wear and when to where it.
But even overall there has been a "casualization" of America. Even the elderly are dressing in track suits and tennis shoes for most situations.
As a child and teenager it was pretty straight forward. (late 50's through the 60's). Jeans and sneakers were play clothes. Slack and shirts were school clothes. You wore a tie to church and sometimes a coat. (This was in Florida).
But today I wear jeans and a polo shirt to work with tennis shoes. But what I wear and what I think is appropriate are two different things.
So to answer the questions:
I think a suit and tie is mandatory for weddings and funerals. And job interviews.
Dress shirt and tie? Office work. Church.
Tennis shoes out of the question? Any time it's not appropriate to wear jeans.
Walking shorts? Maybe if you're out for a walk.
Caps and hats? If you're wearing jeans you can wear a ball cap. A nice hat can be worn almost anytime. However!! Take off your hat in church, at the office, and at the table!! I hate ball caps on people sitting in restaurants.
T-shirts vs collared shirts? T-shirts are for play or for manual labor. NOT appropriate for the office.
Tucked vs un-tucked. Depends on the shirt, but tucked in any situation that calls for slacks. But untucked is almost necessary for concealed carry. Fortunately open-carry is perfectly legal in Arizona and you're not going to be hassled too much if your gun is spotted.
Button down vs non? Button down shirts should be worn if you're wearing a tie. Unless it's a bolo tie.
Ok, there's my take. Of course as I said I don't even follow my own fashion advice. But as I gained weight I've cared less about appearance and more about comfort.