First practice in a closed space with few distractions. Throw the ball and say "Go get it!" and patiently (and quietly) wait for your dog..

Do not chase your dog, instead wait nearby for him to relax as much as possible and presenting them with a strong smell (chicken, bacon..

Start by first considering the root of the issue (most commonly boredom, uncertainty in a social setting, confused, overtired) and guiding..