Above all else, I like it when my cocktails are simple. I like simple, quality ingredients without a lot of fuss in putting the cocktail together. Regardless of the season, hot or cold, I like to make a Negroni cocktail. If you do your homework, other blogs dedicated to mixology will provide you with much more insightful information about the Negroni than mine. My backstory on the Negroni is that it comes from Italy, it's simple to make, and it is damn good.
The Negroni has gained in popularity recently with the ascension of other craft cocktails. There are white Negronis, standard Negronis, and Negronis with various fruits in them. I like my Negronis simple. Just Gin, Campari, and sweet vermouth, that's it. While most recipes will keep all of these ingredients in the same proportions, I prefer to skew mine more towards the gin side of the equation. Finally, I prefer to use the most expensive ingredients I can reasonably afford for my cocktail making.
Negroni recipe
1oz Gin (preferably something premium like the Botanist)
3/4oz sweet vermouth (I used Carpano Antica and it is amazing. If I'm going cheaper I'll use Dolin Rouge)
3/4oz Campari (there are no substitutes in my book)
As stated before I'm simple... I combine all of these ingredients in a double old fashioned glass, swirl them around and then throw in a big handful of ice. That's it. I particularly like the way the cocktail's flavor changes as the ice melts into the drink. If you don't like it as diluted but like the beverage cold, then use a giant ice cube. If you like it to dilute and chill faster then use crushed ice. I like to experiment with my cocktails and play with the balance of ingredients before I decide on what I like.
If you want to be a purist, garnish with a lemon peel... I like it just the way it is above.
Remember, quality ingredients make quality cocktails. Don't believe all those people that say a specific alcohol is "too good" for a cocktail. Drink what you like how you like it.