Did you know margaritas are not supposed to be neon green or day-glow yellow? Try making your own margarita mix with two parts fresh lemon or lime juice and one part triple sec liqueur. Or if you must use a pre-made mix, try buying one made with all-natural ingredients, and the less sugar the better.
go grand
Another great way to upgrade your margaritas is to substitute a fine orange liqueur such as Grand Marnier or Cointreau for that old bottle of triple sec that's been collecting dust in your liquor cabinet for years.
give 100%
If the thought of drinking tequila brings bad memories of slamming shots on spring break, know that all tequilas are not the same. Look for 100% Blue Agave tequila vs. cheaper blends that are mixed with inexpensive (and hangover inducing) ingredients.
young vs. old
For bolder flavors, try an un-aged blanco (white) tequila instead of more traditional repasado (rested) tequila that's been barrel-aged a minimum of two months, or the more expensive anejo (aged) tequila that's been barrel-aged for at least a year.
Notes
I love to salt the rim of my margarita glass by rubbing lemon or lime around the edge and dipping it in a saucer of coarse salt. If I need a sweet and salty fix, I mix 50/50 salt and sugar.