Every leather jacket buyer has his own agenda. A lot of guys are looking for something they can wear out to bars and clubs. Others are looking for a piece of outerwear to throw on every morning. The important thing is to know which look you want.
The Rocker Look: Your leather jacket should pair well with an undershirt, the shirt you wear while changing the oil in your car, any shirt you wear to a concert, and – if you really want to go for it – a fitted henley. As long as you avoid shirts emblazoned with the words "No Fear" or energy drink logos, you'll end up looking ready for a night on the town without appearing to be trying too hard.
The Professional Look: Pairing your leather jacket with an oxford shirt and tie can be tricky, but it's not rocket science. Just consider whether your wardrobe is well suited to a tighter-fitting jacket. You'll want narrower shirts and skinnier ties. A bow tie isn't going to work and neither are pleated khakis. You don't want to look like your torso is rebelling against your legs. Keep in mind that this is never going to be an acceptable outfit to wear to a board meeting unless you work at a successful record label.
The Downtown Look: If you pair a leather jacket with torn denim then smoke eight cartons of cigarettes a day for three weeks, you can look like Iggy Pop, circa 1973. That's fine, but we'd recommend sticking to dark, narrow, and tear-free jeans. Do not attempt to wear "Dad jeans" with a leather jacket. Romney lost.
The AC/DC Look: You could wear your new jacket with shorts. Please don't.