Here more on the ingredients//recipes:
The Vesper Martini: Three measures of Gordon’s, one of vodka, half a measure of Kina Lillet. Shake it very well until it’s ice-cold, then add a large thin slice of lemon peel.
Original recipe from Ian Fleming’s James Bond in Casino Royal. I can’t recall if it was in the books, I read them as a kid but the shaking not just makes it ice cold (due to surface area contact with ice) but it also dilutes the drink; increasing the volume of water in the mix.
I was in a fancy steakhouse bar years ago, ordered a martini. The guy just shook vodka and ice. Might as well have ordered a vodka rocks.