Button your flannel as usual before choosing a crewneck. The triangular area between the top button and collar points is where the tee will show. A high inner neck can fill the opening; a deeper...

A white stripe in the plaid and a white tee can pull an outfit together. But a bright optical white against muted rust and tan can look like a separate layer pasted on top. A...

The annoying fold usually forms as you pull the second sleeve over the first. It can stay perched above the biceps all day. A smooth shoulder and an inner sleeve narrower than the flannel arm...

The same flannel can be a light jacket on a cold morning and an indoor overshirt by lunch. The tee beneath it sets the warmth and bulk for both. Heavy cotton gives the open shirt...

An open flannel leaves most of the tee in view; button it and the shirt beneath suddenly has to share every inch of sleeve and chest space. Choose the T-shirt for the closer of those...