One of the most essential elements of design is making sure everything is scaled (aka sized) properly in proportion to the room and to the other pieces in the room. How many times have I seen a "before" room with a weird mixture of too-large furniture with too-small furniture and a tiny rug to unite them all? Too many times. Young House Love just shared their new living room rug purchase, and it's a great example of changing the scale of one element and how it makes everything look better.
Their first rug:
And the new rug:
See how the sofa dwarfs the smaller rug and therefore looks big and hulking? When the perimeter of the rug extends beyond the sofa's footprint, the sofa looks more in scale and looks chicer. I also like that the desk in the corner looks more involved with the rest of the room now - the first rug seemed to form a barrier around the sofa and not extend into the room as a whole. I also like the lighter color of the new rug, and it's nice to see some pattern.
Excellent job, Petersiks!