How can we make this fairly ordinary chair look more interesting? We could give it some buttons!
Select verts that are nicely spaced out on the chair cushion
And chamfer those dang verts! They may or may not give you polys that aren't nice quads and tris (we'll address this soon).
Then select those verts (or the inner faces) and push them in! No need to extrude, though you may if you want a smoother angle gradient.
Now we can add some pretty buttons. I like quad spheres to I jammed some of those in.
Now stick that piece of furniture in your room! Note that I've triangulated my mesh so Unreal won't give me a hard time. Time to make this sad grey room colorful!