Uniqlo has amazing men's shirts for under 20$. They're in a million colors and patterns great for your man.
I have two different plaid flannel shirts from Uniqlo, and I love them both. They are super comfortable, and perfect for lazy days. The colors that the flannels come in are all really cute, and my only complaint is that it feels a little flimsy.
Winters in NYC are so brutal, because you're exposed to the elements all the time. I was getting tired of bundling up to go out (undershirt, tank top, blouse, sweater, with thermal leggings under jeans. Talk about bulky!) because I'd be too hot on the subway and too cold outside. One day I tried a Heat Tech camisole from Uniqlo, and it has changed my life. It keeps so warm when I walk around, and is thin enough to wear under anything. It comes in many different cuts and colors, that you could probably wear it as your primary shirt! My *only* gripe is that they are a tad too short for my long torso.
