Gin
Juniper first, then everything else.
How it's built
Most gin starts as a neutral spirit and gets its character from botanicals added afterward. Some producers infuse with essential oils instead, which is cheaper to produce and generally considered the less refined route.
Juniper is always the lead. Around it you'll commonly find coriander, angelica, grains of paradise, cassia, orris root, caraway, and elderflower. Once distillers started reaching for cucumber and rose, the category cracked wide open. Now you'll find gins built on apple brandy or malt bases and flavored with everything from mugwort to sarsaparilla.
London dry
Despite all that invention, London dry is still the dominant style: a completely neutral base spirit with flavoring added after. Expect it to be less sweet than other varieties and higher in alcohol, usually with citrus peel among the botanicals, which you can often pick up on the nose.
No spirit has gained more from the craft distilling boom, whether through unusual botanicals like spruce tips and chiles or through barrel aging.
How to mix with it
Gin is herbal, woodsy, and loud. Trying to hide it is a losing fight that leaves you with a clumsy, inarticulate drink. Work with the character instead: surround it with floral, herbal, and vegetal elements, cut against it with fruit and spice, or fall back on its most dependable partners: citrus, vermouth and bitters.
That volume enforces a rule worth carrying everywhere in cocktail making: err toward simplicity. You'll find exceptions in this collection, because the craft movement exists to break rules, but you won't find a good gin drink that asks the spirit to carry too much at once.