Well, the provided context from YouTube is about as helpful for drawing a sofa as a fish is for riding a bicycle, offering little more than copyright information. So, let's disregard that and get to the real artistry of sketching some comfy furniture.
First, think of a sofa not as a single, complex object, but as a friendly collection of rectangles and cubes. Start with a long, low rectangle for the main seating base. To give it some life and prevent it from looking like a flat plank, use a bit of perspective. Make the lines on the side angle slightly inward as if they're meeting at a point far in the distance. This one simple trick will make your sofa look like it actually exists in a room and isn't just a 2D symbol.
Now, let's make it comfortable. On top of your base rectangle, draw the seat cushions. These are just flatter, puffier rectangles. Don't be afraid to round the corners a bit to make them look soft. Add another set of taller, squarer cushions standing up behind the seat cushions for the backrest. Flank the whole thing with two shorter boxes for the arms. You've now created the basic, blocky skeleton of a sofa!
To complete the "set," simply repeat the process on a smaller scale to create a matching loveseat or an armchair. Maybe add a simple coffee table (another box!) in the middle. Finally, bring it all to life with details. Add subtle lines for seams, little circles for tufted buttons, and some light shading under the cushions and beneath the sofa itself to give it weight and depth. Before you know it, you'll have a full living room suite on paper, ready for tiny, imaginary guests. No allen key required.
