If you are lucky enough or, if some of the maintenance stories I hear are to be believed, maybe unlucky enough, to be the proud owner of a bach, crib or shack near the sea then you'll know what a liability the wrong kind of garden can actually be.
With the elevation of some of these dwellings to "beach house" status there's probably a little more opportunity to create a bit more of a garden space. The advent of modern irrigation and timers helps. But even then a failsafe approach will see you focus any coastal gardening exploits on salt-hardy plants. And, by proxy, salt-hardy also means wind-hardy and drought tolerant or dry-hardy. Hardy, hardy, hardy...
First cab off the rank is the agave family, plants with a thickset, succulent type foliage that has a distinctive central foliage point resembling a rhino horn with thick sculptural foliage peeling off to form a proud crown. It is as tough as the proverbial brick you know what.
Agave are easy to grow, will love the sand and look good next to hard surfaces like fences and buildings. Seriously, the best bit is they are pretty much the next best thing to plastic plants (in a good way).