I know many parent use the counting approach. “I am going to count to 3. By the time I reach 3 you better… fill in the blank.” Here is the problem with this approach. It gives them time to keep disobeying. You start negotiating with them by saying, “1, 2, 2 and a half, 2 and three quarters…” This approach drastically weakens your authority. They learn that they can easily bargain or negotiate.
I counted with my child but I only said “One.” He knew, because of my consistency with immediate consequences, that “one” meant obey right away, all the way. If I wanted him to get out of the crowded community pool all I had to say was “one”. He jumped right out because he knew if he didn’t, the behind-the-scenes consequence would be no media for 24 hours. Every time he disobeyed and he lagged, he got that consequence. I trained him because I was consistent in my consequences. You might think this is too much work for you, but guess what? You only need to do the consequence 2-3 times and he will get it.