Try stuff on. "One of the guys who helped me start the business flew up this weekend, and I was like, 'These are the pants. You have to try them on.' And he said, 'I'm not a skinny-pant guy. I like my stuff baggy.' I was like, 'Just fucking try the pants on!' and shoved him into the dressing room. And now he totally gets it. You have to try clothing on to know how it fits and feels."

Chinos are your friend. "Anything you can wear denim with, you can wear chinos with. They're not dress pants, they're casual. That's what's so American about them."

This is what you need in your closet. "A perfect white crewneck T-shirt. It should be slim but not tight, and a little longer than a regular undershirt. A pair of rigid indigo jeans, maybe with only one rinse. Chinos, of course. A vintage military jacket. A navy V-neck cashmere sweater. And a suit, fairly fitted, with a slim pant—that's something you should spend money on."

Getting dressed shouldn't be hard. "Sometimes—and I say this a lot—I wish I were a guy. It's the easiest freaking thing on the planet! Just keep it simple. If you're really confused in the morning, just put on a pair of jeans and a white T-shirt. Think Paul Newman. You're an American dude, you should dress like a dude. Jeans, T-shirt. Chinos, T-shirt. It's so easy. Even on dressy occasions, you could be the coolest dude in the room by not being overly dressed up."

There's nothing wrong with wearing a uniform. "Men are handsome in uniform. A suit is a uniform. Military is a uniform. Why was that schoolboy-prepster thing so hot? Because it's sort of a uniform."

Go easy on the woodchopper look. "You have to do it within reason. Don't go out and buy shit that you didn't wear down yourself. That's inauthentic. If you're going to look like you chop wood, then you should be able to chop wood, start a fire, all those things."

There are certain things every guy should be able to do. "A guy should know how to grill a steak. A guy should know how to put up shelves. I think it's weird when a guy doesn't know how to do that. Also, a guy should know good manners. Like, to open a car door, or the door to a restaurant. That's what girls talk about, anyway."

Read More:
The Khakis You Can't Live Without
The Details Guide to Laid-Back Spring Style
Rules of Style from J. Crew's Jenna Lyons