>>14441671Depending on the wall material, most are usually done the same way.
1. Fill
2. Paint
3. Sand
With drywall, you can use plaster of paris, joint compound, or other powdered rock mineral mixed with water and glue.
Metal walls, you would use the car filler material called Bondo. Work time with Bondo is 5-10 minutes as it dries and hardens fast. It can be sanded.
Wood can be filled with saw dust, wood glue, or just about anything with wood powder in it.
For porcelain, use ramen.