Let them swing the bat as much as possible as often as possible at 10u and 12u. Some parents will look at you funny, but as many great players from island countries have said, "No one has ever WALKED off the island. You must HIT your way off the island". DD walked a ton last year in travel ball the first 3 quarters of the season. almost no hits. She worked hard on hitting. Developed a little confidence in her hitting, but had to make more outs to do it. So instead of 1-2 with 5 walks, she would go 2-5 with 2 walks. No one gets playing time in middle and high school because they can walk. I tell my DD that even if she cannot tie her on shoes, if she can hit, she will get to play. Don't swing at bad pitches, but you don't become a great hitter walking. JMHO