We want to help our children learn to do a job well. We pretended to be a couple of the children and demonstrated poor working habits, contrasting them with good working habits. Then we purposely messed up the den and allowed each child to come in and clean it up as fast as he could, timing him. We demonstrated time-saving motions and encouraged them to use them. They all did a very good job, from the oldest down to the youngest.
Young children are notorious for messing up the house.
It also helps to create special play areas using a small quilt or child-sized table and chairs in the main homeschooling area. This confines their toys to a specific area and they enjoy being in the center of things. They can be taught to play quietly, or to go to another room if they're distracting the rest of the children. Be consistent in training children to help with chores. I had years when I'd wonder if my kids would EVER get to the point where they wouldn't need supervision or to be reminded.