You’ve seen it before—mostly at business-casual functions. Dress shoes with jeans. And while you notice it, if you haven’t tried it, you might feel strange in trying to get the right combination to make it work for you.

Red Moose has a look at four rules to follow to pair your dress shoes with a smart pair of jeans for the ultimate in comfort-cool.

1. You Need the Right Shoes

You don’t want to pull your best Oxfords out of the closet if you plan on wearing jeans. Some Oxfords, especially ones of the suede variety, may work since they don’t look quite as formal as ones made of patent leather, but generally, opt for a more casual shoe like a Derby, loafer, or a boot. If you like the Oxford look, go with a Derby, as they have a similar look but are a bit more casual.

2. Pair the Right Type of Jeans

The main rule here is to not go too baggy or too much of a relaxed fit. The best jeans to pair with dress shoes are straight jeans or slim-fit jeans. Don’t go too small either, as skinny jeans tend to make dress shoes look too big. As for the length, make sure they aren’t too long and end up dragging under the shoe.

3. Think About the Whole Outfit

Because you have dress shoes on, you can’t be too casual above your jeans. A collared button-down shirt or even a dress shirt are fine options, and you can even pair it with a sports jacket. On the other end, don’t get any more casual than a nice polo or golf shirt.

4. Complete the Look

Just like when wearing more formal clothes, you will want to match your leathers. The best way to do this is through a belt. Chances are, you will be wearing brown or gray shoes, as black lends to more of a formal feeling. Match your color and try to get as close as possible with the material so your shoes and belt complement each other.

Finally, remember, the most formal you can go with this look is business-casual. If business or formal attire is requested, that means that you may not wear jeans.