When you find yourself designing new cocktails for home consumption, the first thing you should do is immediately stop what you are doing---remember, someone else has already gone through the trouble of making serious errors in judgement, so you don't have to. These are the people we call "saints".
If you are in a bar with a signature cocktail menu, however, you may ignore it at your peril. Falling into the trap of a specialty cocktail menu is much more hazardous nowadays, as the size of the glasses being served is racing out of proportion with the size of the patrons. With the advent of swimming-pool-sized glassware, it appears both sides are intent on losing.
The true connoisseur knows it is the first moment of the first sip of a properly-mixed cocktail which approaches the Platonic ideal. (It is the last sip of the last cocktail that usually ruins it.) Thus, the one-sip cocktail holds the most promise. One benefit of much smaller cocktails is that this will conveniently allow your server to ignore you at a much faster rate.
But getting back to the saints---their local hideout, often referred to as "The Firmament", has somewhere in the neighborhood of a billion stars. This is hot real estate indeed. This fact is relevant in that a billion approximates the number of different drinks now being proffered by mixologists currently within shouting distance---most of which are no good.
So if you are to have a drink poured into a glass and down the hatch (this being the preferred order), which should it be?
The expert cocktaileur is well-prepared to answer this question. Having generated relevant criteria ahead of time, he may select only those cocktails reaching a necessary minimum positive score.
Suppose your desired list contains the following attributes:
First we'll calculate scores for two typical 20th century "classic" drinks...
Mai Tai: beautiful, exotic, ethnic, refreshing, mood-setting, aromatic, tasty, etc.
Gin & Tonic: beautiful, sophisticated, ethnic (that is, if you consider WASPs an ethnic group,) refreshing, mood-setting, aromatic, tasty, nose-tickling, proper mouthfeel, etc.
... then we'll calculate scores for two typical 21st century modern "designer" drinks:
Hibiscus Blossom with Gin & Maple Syrup: aromatic, exotic, etc.
KFC Martini (fried-chicken infused martini w/ mashed potato garnish) bizarre, revolting, bad for the skin, etc.
The typical "classic" cocktails have scored well, and the typical "designer" cocktails have not. We can see from our analysis that the modern KFC Martini, therefore, is not a very promising drink.
In fact, the shorter version of the same idea would include merely a list of our senses and require that a drink appeal to at least two of them---including a sense of decency.
Which brings me to my final point. Cocktails are for being mixed and drunk-up with your friends, and hopefully not vice-versa. Let's leave designing to cars & clothes. Otherwise, at night’s end, you may discover that the modern cocktail and its aficionados actually have *their* designs on *you*.