If you get as far as the Uists and the weather is fine then get to the south western coast to enjoy the long, usually empty sandy beached. Awesome sunsets!
These beaches have no houses or facilities and can catch the wind, but the lack of anything but sand, waves and views makes for a pretty incredible experience! You can walk for miles along them and there are places you can swim.
Arrive for late sunset in the summer for a once in a lifetime memory.