Make sure the chore is right for the age and abilities of the child. Make it simple with only the number of
steps the child can handle.
Make sure the chore can be safely done, including the safety of materials needed.
Describe exactly what the chore is. Show the child how it needs to be done in order to be done well. If the child is old enough, you can write down the requirements using words or pictures. For example, cleanup after Play-doh: 1) put dough back in containers, 2) make sure lids are on containers, 3) put containers on shelf, 4) wipe off table.
In the beginning, require only 1 or 2 steps until you see that the child can handle the job. Then add the rest. For example, if the children are very young, they might only be asked to help wipe down the table (with you wiping right behind them to make sure all parts are reached).,
Always show that you appreciate the job done well. When you can, make a point to tell others in front of the children about what a great job they did.
Have the child re-do any part of the job not done as well as it could be. No criticism about it, just a matter-of-fact requirement to re-do it followed by full appreciation.