Here is an image I did with a beach,this the kind of scene you'r after? The beach is a terrain object with a sand texture applied,have to use the scale texture feature in the material editor to get a good close up sand effect, you may have the scale set too low thus giving you a large blurry surface.If your cliffs are too rounded use the erode brush in the terrain editor too rough them up a bit.For the waterfall you will find a link on how to create one in the Tutorial sections on this site(think they moved it under Features/Directory).Hope this helps you a little,not very good at explaining things :)