I've been reading some old Ian Flemming James Bond books. Some are spot on for the movies and some are WAY off. James doesn't show up in "The Spy Who Loved Me" until near the end.
In "Casino Royale" Bond orders his classic martini. Alas, I didn't bookmark the page so I can't find it again easily. But that's what Google is for. Alas, 50-some years have passed since that book was written. Formulas have changed. You can't make the same martini. But there are some substitutions that can get you close.
Follow the link and I'll let this person explain.