This is the most basic step in the method. Simply solve a layer, using any method that you know of.
When Waterman described his method, he solved the L layer as such:
If you're colour neutral, this shouldn't take more than two moves. This is because you don't actually include the centre piece with the two corner pieces, and so they can be anywhere on the cube.
Again, this is a very basic substep. Ideally you should be able to solve both corners simultaneously in most cases, but sometimes it's more efficient to solve one corner before the other.
Once again, this is fairly intuitive, but the question is when to solve the centre. Waterman described solving the centre along with the second edge, but it's perfectly feasible (if slower) to solve the centre before any edges.