Place 2 blocks of any solid material for the toilet base
Put a stair block facing outward for the toilet seat
Place a trapdoor above or behind the stair for the tank lid
Add a button or lever on the side for a flush handle
Place a cauldron in front of the stair for the bowl
Fill the cauldron with water if desired
Add a sign or item frame nearby for decoration
Use quartz, stone, or white concrete for a cleaner look