Most home bars fail for the same reason: too many bottles that never get opened and not enough of the basics. Start small and build around the drinks you actually like.
The tools
A two-piece shaker tin, a 30/60ml jigger, a Hawthorne strainer, a bar spoon and a sharp peeler will cover nearly every classic. Buy decent quality once and they will last for years.
The first eight bottles
A good gin, a bourbon or rye, a white rum, a blanco tequila, sweet vermouth, an orange liqueur, Campari and Angostura bitters. With fresh citrus and simple syrup, that list makes most of the drinks we teach in the Weekend Cocktail Starter.