By having structured commands/ words which are used by the mummys and daddys and even the wee ones of a household it will help in the long run in basically telling your dog what is going on. Dogs can be willful just like people, but the biggest problem in owner-dog relations is that the dog is confused and doesn't understand.
Consistency is the best way - short words, no harsh tones - even if they are bad - change your tone. Keep the words the same. Also be careful of your hand signals as some dogs may find it threatening.