Photographing the ocean (usually) is a type of action photography as the scene is constantly changing. Water reflects and smooth water provides the best definition of whatever is being reflected. Although they nicely reflect sky color in general, most oceans I've visited are far from smooth. However, the thin layer of water remaining on the sand immediately after a wave recedes is often quite smooth and can provide some definition of the colorful clouds, the subject most often desired to be reflected. Consider timing the capture of some of your beach images for this wave position.
Another beach photography consideration is what the leading edge of the waterline looks like. I like the frothy white roll clearly delineating the sand and water as seen in this image, but other options can also work well.
I always find a great sunset to be photographically irresistible.
Islands often have very long distance views of the setting (or rising) sun, making them ideal locations for watching this time of the day through a viewfinder.