Martinis should be stirred, not shaken. Don't shake the martini; you'll bruise the gin.
God Len is so cool, NASA has him on a retainer just in case some dumb astronaut accidentally raises the ire of a extraterrestrial race of 12 meter tall humanoids in battle suits. He doesn't need protoculture, he is protoculture.
and only the breath of vermouth -- swish a half-shot around the glass then pour it out before adding the gin (stirred with ice, not shaken, and then strained into the glass) -- and if you must use vodka nothing else changes. If pressed though... I'd have to say... a twist of lemon for a gin martini, and three olives for a vodka martini. Otherwise, exactly the same, and no shaking. Fleming wouldn't know his ass from a good cocktail if it walked up the beach wearing nothing but a white bikini and a diving knife.