Get Down Low: I've said it before and I will say it again, "it ain't nature photography until you are getting your knees dirty." Lowering your viewpoint close to the ground is one of the easiest things you can do to improve your composition. Try using a wide angle lens and catch the waves rushing across the sand inches in front of you. Get down low next to that interesting rock formation at your feet and make it seem larger than life. Go get some sand on your pants and pebbles in your shoes. You will come home with some great images. Just remember to keep an eye on the waves and the camera out of the salt water!
Get Up High: Photographers spend most of their time on the beach when they are at the coast. You can consistently get great images on the sandy or rocky shores but don't pass up opportunities to shoot from the bluffs above. You can use wide angle lenses to include the details on the ground near you as well as the beach below. This is also a great opportunity to pull that long telephoto lens out of your bag and shoot down the beach. Longer focal lengths compress the foreground and the background, creating some very unique and interesting effects. But please, please make sure your tripod is secure when you are close to the edge of the cliff. I learned that the hard way (a story for another time).
The next time you are visiting the ocean's edge, try some of the techniques above and create some images that live up to your memories.