Our goal is to get our horse to work with us so well that it will look like he can read our mind. If we're shouting commands at him, though, whether with our voice or body language, everyone can read our mind, not just our horse.
Whatever signal you're using, try using it in a lighter manner and see if you can get the same response. So if you normally wave your whip to get the horse moving when you're lunging him, try just waggling it.
The beauty of teaching the specific "go forward" cue (tapping the hip with a whip to signal go, then stop tapping the moment the horse takes a step forward) is that you can eventually back off enough that you can tell the horse to go forward by just focusing your eyes on his hip and thinking about him going forward. It will feel like mental telepathy. Can't get much lighter cue than that!
Try using your normal rein cue, but with less pull. Ride an "S" or figure eight, making several changes of direction, and see how light a signal you can use and still have the horse make the turn. Slow your hands so that you reach for the rein more slowly or take the slack out of the rein more slowly. That gives the horse time to respond. But then see how quick you can be to release. The quicker you can reward the horse, the less intense a cue you'll need.
And if you're used to yelling at your kids or dogs, why not try a softer voice? They probably aren't hard of hearing any more than your horse is hard of feeling. A lighter cue and a quick release may make everyone's life a little easier.