The “Miner” has been the go to design for Minecraft Seating since the beginning. These simple to make seating usings Stair Blocks, with Signs on the side.
Because of the wide range of Stair Block types, and Sign colours, there is huge variety of styles available.
You can extend the chair into a Couch, by using more Stairs…
The single seat version below has a red and black Throw Pillow.