When we train handlers to work with their service dogs, we show them both the hand signals and the words to use. Dogs actually understand hand signals much more easily than they do words, so we created a beginner handout which only describes and shows the hand signals so that the handlers can practice without words. This way, the handler is much less likely to use multiple words or to repeat their cues. Note that we use the word "cue" instead of "command" because we use reward-based positive reinforcement training methods, not punishment-based methods.
You can download and even distribute this handout, if you wish.