Painting foreground hill and cliff
Painting the foreground hill starts by painting the trees on top of the hill, using the side of your brush utilise the texture of the paper to help create believable tree shapes. Once the tree area is done, paint diagonal strokes with watercolor mixes of Burnt Siena , French Ultramarine, Raw Umber and even some Alizarin Crimson for the side of the hill or cliff face.  Leave some highlights on the face of the hill and make sure you use different consistencies of pigment to give the cliff face some interesting variety of shapes. Remember, by moving you brush quickly over the paper you can create different textures which can be incorporated into your painting.
Now paint the sea. First pre-wet with clean water, the area where the sea water hits the sand. Colors used for the sea are French Ultramarine in the distance with French Ultramarine and Cobalt Turquoise for the water closer to the viewer. Use swift relatively horizontal brush strokes when doing the sea so you can leave some broken white edges that will be read by the viewer as foam.
As you paint the sea near the shore the watercolor paint will hit the wet area on the sand and hopefully result in some nice soft edges in the foreground. You want some sharp edges in the distant shoreline near the main cliff face, so do not pre-wet that region of the painting.
While the foreground water is still wet drop in some reflections of the hill side.
With a creamy mix of Burnt Sienna and French Ultramarine paint the rocks in the sea. While sticking roughly to the rocks in the photograph I have no problem moving them a little to take advantage of any white areas in the sea which can act as spray on the rocks.
Continue to: Final steps of this watercolor seascape painting