One of the main differences between traditional and modern furniture is its materiality. Contemporary designs, which tend to be more streamlined in their approach, can lack the rich and idiosyncratic character of classic pieces. The key is to combine the two, playing with the contrast and finding a balance in a sleek and understated way.

There are some basic rules of thumb. Classic pieces typically use a lot of wood and upholstery, which makes them heavy, durable and tactile—ideal for standout pieces and items you touch a lot, like a dining table. Then it’s a good idea to pair your classic table with chairs that are simpler, so they don’t battle each other.

Conversely, if you’re choosing a sofa, opt for a more minimal design that’s neutral in color and material and add a pop o...