Beach living rooms are most warm & welcoming after a chilling, ocean swim.
Almost certainly your beach cottage will have a fireplace.
If it doesn't, don't despair...you can always put a firepit in the sand or a free standing fire pit on your porch or deck. It really is warming after a day in the ocean.
Have some nice throw rugs on the floor that are sand friendly. After you settle down for the day you can shake them out and all is good.
Try a nautical, seaside flair on the walls...maybe a faux mural that reflects an ocean scene.
Or perhaps you might like a seaside wall paper, putting different styles together that you can mix & match.
The wall accents are really a no-brainer...anything ocean or sea...driftwood, shells, netting, etc. Shelving where you can display your seaside keepsakes.
Bead board or a light paneling is also a nice touch to walls in a beach setting...it's clean and well trimmed and just plain looks nice!
Your beach living room won't have the right atmosphere if it's not illuminated properly. Of course, during the day you have the spendor of the sunshine but what about at night?
Track lighting is a nice touch when you have little space. You can run tracks almost anywhere and now they even have bendable tracks so you can go around corners...
Nautical or seaside themed table lamps are a nice touch and also paper lanterns. They go well anywhere, outside on the deck or patio or to light an obscure hallway or pantry. They are also very inexpensive!
Walk the beach for some beach glass or driftwood for a nice lamp design...why not make it yourself? It's very easy to
put a lamp together and it would be one of a kind. I'll cover more on that in one of our projects.