Where you place your leg, will also determine how your horse is supposed to respond. Using your legs doesn't just mean "go", it entails how your horse uses his body as well. Leg aids will be pretty spread apart in the beginning, if he doesn't know how to respond to them, but Once he knows the cues, your leg placement can get closer together, but for training sake, put those cues further apart, so he can distinquish easier. Ask-tell-demand, as has already been suggested...light pressure, to more firm.
Now if you are wanting the horse to move his hips over, you want to be asking near his rear cinch while you are teaching him to respond to that cue. If wanting the right hip to move, push the left side, if wanting the move the left hip, push the right side.
If wanting to move the shoulder, place your foot a little ahead of the front cinch at the beginning of teaching to move the shoulder. If you are wanting to move the left, push the right side, moving the right, push the left.
If you want to move the body side ways, push the horse's side right behind the front cinch. Use the right side to move to the left, left side to move the right.
That's the way I train my horses, and once they 'get it' I move the cues closer together, until they are eventually very close together, and you don't even really see the shift in leg cueing.
"The ideal horseman has the courage of a lion, the patience of a saint, and the hands of a woman..."