To make a decent drink, you will need decent ingredients.
You can find most of the bottles you need at a good off-licence, or even a larger supermarket, nowadays. But for those harder to find bottles, a number of specialist retailers exist (London-based recommendations at the moment; it’s where I live):
Gerry’s – Really, the only shop you need when in London. Gerry’s has been a London landmark since it opened in the early 80s, but its true pedigree dates back to the original Del Monico’s store that opened nearby in the 1950s, where Michael Kyprianou served as the manager before opening Gerry’s. The staff are so knowledgeable on all of their stock that shopping there is always a chance to discover something new.
Selfridges – Shopping in Selfridges is a pleasure anyway, but the basement-level wine & spirits section houses a wide collection of spirits and some enthusiastic staff. Their collection of gins rival Gerry’s in its comprehensiveness. Their cookware department also stocks everything you need in the way of shakers, bar equipment & glasses.
The Whisky Exchange – online, but with a shop in Covent Garden (the original shop in Borough closed at the end of December 2015). As the name suggests, their main line is Scotch whisky, but they also stock a large range of whiskeys, too. Particularly good for bourbons & rye whisky, I find.
The DrinkShop – online only, but perfect if you are unable to visit the stores above. Their delivery charges are a reasonable £4.99 per order, and their stock, especially of bitters, is incredibly wide. You will also find a wealth of information on all drinks, including over 1000 cocktail recipes.
Drinkstuff – again, online only, but absolutely everything you need for bar equipment, from perfect small stainless steel measures to beer bongs. Delivery charges are very reasonable, and their starter ‘bundles’ for shakers and basic equipment are good value.
Neal’s Yard Remedies – a fantastic source of ingredients for bitters. The shop in central London is worth visiting as the staff includes a number of herbalists who are happy to give advice on extraction methods and the required herbs, barks and other flavouring agents. Everything is also available via the website.
Baldwins – London’s oldest herbalist first opened their doors in 1844. The shop is now a great source of ingredients, plus all of the storage and dropper bottles required for your bitters recipes. Again, everything is available online as well as via the shop.
Wood Barrels UK – If you fancy trying some barrel-aged cocktails, which seem to be featuring heavily on the lists of most cocktail places right now, then a small wooden barrel is a good place to start. Wood Barrels can supply oak barrels just right for experimentation.
Star Child, Glastonbury – A supplier of magical necessities, incense & other New Age items, but also a good source for unusual herbs such as hyssop & the impossibly hard-to-find sassafras. Again, reasonable postage & package charges and a rapid service.
Cocktail Shop, Barcelona – In the trendy Eixample area of Barcelona, this comprehensive shop offers ingredients, tools, wonderful travelling bar kits by BIP & even courses & sessions on mixology. Their range of bitters is quite remarkable. Stocked by people who really know their subject and current trends. Well worth visiting in a city that has cocktail culture pretty well perfect.