I am mostly casual, usually wearing jeans and a long sleeve colored shirt. I think I've seen people call them sport shirts??? Maybe I'm mistaken. Anyway, you know the kind; they might be checkered or striped and in all different colors. I have always felt super weird putting ANYTHING over a shirt like this, so in the past during fall/winter when I have wanted to wear a jacket or sweater, I have switched out of that shirt into a plain t-shirt, and then put on the second layer. Is that weird? How would you remedy this? What looks good and/or is appropriate to wear over that kind of long sleeved colored and collared shirt? More casual, no blazers.