Tequila is such an amazing spirit with a colorful history. Make sure you are buying the good stuff. It needs to be 100% agave - don't be fooled by the other crap. You know that salt and lime shit people do with a shot of tequila? It's only to cover the taste of lower quality booze. Don't use salt and lime if you have a good quality tequila. Unless, of course, you just really like salt and lime. Then, use away. Weirdo.
Add a shot of quality tequila to a glass. Add a splash of water or an ice cube. Sip with dignity.
Basic Margarita (taken from The Drunken Botanist by Amy Stewart)
1 1/2 oz. good, 100% agave tequila
1/2 oz. lime juice
1/2 oz. orange liqueur - Cointreau, Patron, etc.
dash of agave syrup
Garnish if you feel the need. D likes green olives in her margarita. You do you.
Put all ingredients in a shaker with ice and shake it like you mean it. Strain it into a cocktail glass (with or without the salt rim, you decide) and sip it straight up. Fug yeah. Honestly, the best margaritas are the most simple. Skip the syrups and HFCS filled sweet and sours.