Take three strides: start with the left, then the right, and finish with the left again.
March forward in a trio of steps: left foot, right foot, then left foot once more.
Move ahead in a sequence of three: left step, right step, left step.
Stride three times, beginning on the left, followed by the right, and ending with the left.
Proceed with three steps in order: left, then right, then left.
