What cocktails can I make with brandy, gin, elderflower liqueur, Lillet Blanc, ginger beer, lemon, and lime?

It looks like you have quite an interesting mix of ingredients to work with! Given your selection, a great cocktail to consider would be the "Bitter Elder" (Cocktail ID: 6956). This drink combines gin, elderflower liqueur, lemon juice, and Campari (which you could potentially substitute with Lillet Black for a slightly different, yet still enjoyable flavor profile). The "Bitter Elder" offers a beautifully balanced experience by weaving together floral notes from the elderflower liqueur with the sharpness of lemon juice and the complex, bitter undertones of Campari. Although you don't have Campari, Lillet Black's complexity could give a unique twist. This cocktail is shaken and served cold in a cocktail glass, making it a sophisticated choice for those who enjoy depth and contrast in their drinks.

If you're in the mood for something lighter and more refreshing, the "Elderflower Gin & Tonic" (Cocktail ID: 9124) could be a delightful option. With your gin, elderflower liqueur, lime, and tonic water, you can create an elegant and airy drink. This cocktail accentuates the botanical notes of gin, with the elderflower liqueur adding a sweet and fragrant twist and a slice of lime offering a bit of zing, perfectly complimenting the tonic's crispness. Served in a lowball glass, this drink is ideal for spring and summer gatherings, providing a nuanced flavor profile with a delightful floral bouquet.

Lastly, if you're looking to use your ginger beer, "The Great Lusby" (Cocktail ID: 5361) is another excellent choice. Combining gin, lemon juice, mint leaves, and ginger beer, this cocktail is refreshing and vibrant. The sharp gin is mellowed by the sweetness and spiciness of ginger beer while the mint leaves add a cool, herbal undertone. Serve it in a highball glass with a garnish of lemon peel for an aromatic, invigorating drink. Enjoy exploring these delightful cocktails with your unique mix of ingredients!