These combinations that can be translated in large or small spaces, be casual or more formal, and work for entertaining a crowd or relaxing alone. A classic combo that works in large or small spaces, you can't go wrong with a sofa and pair of chairs.
When the chairs are placed opposite the sofa, this arrangement definitely feels a little formal, and since none of the furnishings face the focal point, it's better used for conversation than television viewing. An L-shaped sectional on its own may be perfect for cozy family movie nights, but they leave an empty spot in the room and can feel off balance.
For this reason, I almost always include an additional chair and orient it toward the sofa (instead of toward the focal point) to promote conversation and balance the space. A round coffee table is a good option for this type of sofa as it lacks hard corners that might get bumped while navigating around it.
For a space that is used for both entertaining and family nights, adding two chairs to a sectional is a great option that provides plenty of seating but feels very casual. Be sure to leave plenty of space for walking between the chairs and the sectional for the best flow, and source a coffee table or ottoman large enough to fill the center (we had this one custom made).
The first item to place is your sofa, and there are two options: either facing or perpendicular to your focal point. We centered the furnishings on the fireplace for symmetry, and placed the sofa perpendicular to it to maintain views to the TV and out to the yard. The room has some odd angles, including the television mounted in the corner, but the symmetrical furnishings lend balance. In the front living room of our Blazing Star project, we did just that with a pair of black cabinets.
The room was little more than a pass-through when we got our hands on it, and our clients wanted a sophisticated spot to welcome guests (the front door opens into the space).