Only neat, room temperature with a little bit of water on the side.
Scotch taste often benefits when it is highlighted by an appropriate hors d'oeuvre. Younger whiskeys always taste a bit rougher, peatier and saltier they are better complemented by something even saltier, like blue cheese, which is an excellent side to almost any younger Islay (Laphroaig 10, Bowmore 12 etc.). Generally, sharp cheeses are a safe bet to make almost any Scotch tasting better. With aging, alcohol content in a whiskey is reducing due to evaporation from the barrel and Scotch becomes mellower and sweeter. Coffee beans and/or chocolate then become a good complement for those.