This is less well-known than Luskentyre up the coast but just spectacular with fewer people visiting
Travel along the A859 until you reach the small car park and walk from there. Alternatively take the South side of the beach and you have both Harris Tweed Shop (https://www.facebook.com/CarolineChafferTweedAndTextilesNorthtonTradingCo/) which is well a stop as it is the sweetest little shop ever and Temple Cafe where you can park as well. This coffee shop in the style of and island black house is super charming as well (T: 07876340416).
Whichever side you are taking, you can stop at Croft 35 in Northton where they have a small shack serving local pies etc. see http://www.croft36.com/location/4573355877
If you want to stay - there is nowhere nicer than Scarista House overlooking the beach which is an owner operated small hotel in a Georgian Manse house - http://www.scaristahouse.com/