To teach him to wait, walk out and pick up at least half the dummies you throw as he sits and watches. All the commands mentioned here are short and distinctive. Preface each command with your dog's name. Hearing his name gets his attention for the command that follows. After a while, he will come to expect a command whenever he hears his name, and he will automatically prepare to obey.
Dogs learn quicker when verbal commands are paired with visual cues.
Always deliver commands authoritatively, but don't shout or repeat commands. Unless he's far away and making lots of noise, your dog will hear you. If he doesn't respond, it's because he's overexcited or doesn't want to obey. Shouting will only excite him more, and repeating commands teaches him that he can ignore you. Make him obey the first time you give a command.