There aren't many drinks where this question would be necessary, but with so many styles, variations, twists and riffs, it can be quite a daunting prospect ordering a martini in a bar and being sure you're actually going to get what you wanted. So, here is a basic guide to get you started.
What base spirit would you like?
Vodka - choose vodka for your martini if you want a crisp, neutral base that allows the vermouth to sing.
Gin - choose gin for your martini if you want a bit more character and flavour to your base.
Dry or wet?
Surely they're all wet?? They're made of liquid for god's sake! Well yes, but in this case, we are talking, "how much vermouth do you want"?
Dry - choose a dry martini if you you want more of the base spirit for a stronger, less sweet flavour.
Wet - choose a wet martini if you want more vermouth, meaning a slightly lower abv, and a little more sweetness (even if it's a dry vermouth).
Dirty?
If you like a bit of filth with your martini, you might like to have a little olive brine thrown in there for a more savoury libation. If this is your bag, just ask the bartender for a dirty martini, and be sure to let them know just how dirty you are. You don't want it coming out squeaky clean when you know you're an absolute filth bag, and equally you don't want to feel like you need a shower after it when all you wanted was a tiny seasoning of salty brine.
Shaken or stirred?
Almost nobody will ask you this question. Most bartenders will assume they will be stirring your martini. This allows for a nice slow dilution. If you're feeling a bit 007 though, absolutely go for it.
Stirred - choose stirred if you would like your martini, slowly and gently diluted and perfectly chilled.
Shaken - choose this if you are wearing a suit and in a casino. Also, if you would like a more diluted style of martini with excessive aeration. A very uncommon choice. I want vodka not water!
Thrown - choose this option if you want some theatre with your drink. The ingredients are poured from one tumbler to another from a great height to allow a more gentle aeration. The best of both worlds. Perfectly diluted and chilled with some light aeration.
What garnish would you like?
Twist - A twist of citrus peel (normally lemon), gently squeezed over your drink to let the tasty oils from the skin infuse your drink. You might want the peel in there, or you might prefer to have it discarded, so you keep the oils, but lose the possibility of accidentally eating a bit of lemon peel.
Olive - Ideal addition if you've ordered a dirty martini, but can very happily accompany a "clean" martini too. If you like olives, have an olive or several!
My personal favourite?
"I'd like a dry vodka martini with a discarded lemon peel please" - that's how I'd be ordering my drink.
Martini cocktail sets with instructions on how to make your own martini at home are available in the Spirited shop here.