Sometimes (a LOT of times ? 🙂 ) children refuse to do your command because of various reason.
If the reason is valid, then you must be fair. But if it’s not valid, then you need to make them do it.
First you have to speak kindly, but firmly, to them.
Use as little words possible, don’t flood them with angry/irrelevant sayings.
Persuade them to do it, WITHOUT lying (believe me, this will cause you serious problems later).
If they still refuse, you can cancel the order if it’s not important. But if it is, then somehow you need to get them to do it anyway.
Some parents will be inclined to use physical force at this point.
Here’s the tip – if you child is ticklish, just say that you’ll tickle them until they do it 🙂
No harm’s done, instead they will laugh uncontrollably while getting the job done 😀
And it’s fun to both of you. What could be better ? Let me know 🙂