What they said. Basically, if you want to draw something that faces North and North is up on your page you could have issues depending on your point of view. It sounds like Ascension is giving you the best advice but, in case he did not hit the nail on the head, you may be drawing from directly overhead. In that case you have to decide if you want to keep the perspective real or tweak it a bit to show depth. If you are keeping it real and the cliffs are straight up and down you really can't see them. The only thing you can do is make the ocean water look different along that area. It is probably deeper there than around the rest of the island. If you show beach between the bottom of the cliff and the water it's going to be a challenge. The best I can say in that case is to get on Google Earth and take a tour of an area that looks like what you want and look at it from directly overhead.

If you want to tweak things then you can make it so the foot of the cliff extends out farther than the top edge and you can draw the cliff using lines and shadows. Most likely going from lighter at the top to darker near the bottom. This is what mearrin exemplified above.

Another example of how to do this and have some beach might help a bit. Take a look at what Mike Schley has done here (see the southern edge for one example).