The first step imo to a waterfall is how mush splash can your pond or design can you control. If your pond is only 3 feet wide then I wouldn't think about a 4 foot waterfall 2 foot would be the max drop. The wind can realy take hold of a waterfal and blow the water in directions or distance that boggle the mind.
If you did more like a stream or had a rock just infront of where the water will land this can catch the splash before the water gains momentum and starts flying all over the place. A simple little splash outside of Containment can cost 100s of gallons a day week or month.
Having tall character stones to the side of the waterfall are a natural looking way of controlling splash and might even limit your wind. That and having the character stones pulled inward toward each other on the outside edges. Making a flatened out horse shoe.
Then have the pond continue to widen this will make any splash have to fly a good distance before if gets out of the pond.
There's another consideration to think about with waterfalls and that is sound a shallow landing in a pooling area will give more of a tinny sound to the waterfall. A narrow stream of water falling into a deep pool will give off more base. And often volume. If as little sound as possible is what you seek then have the water drop onto a rock that's on an angle that's almost vertical and let's the waterfall slide into the pond.