One of the most interesting ways to spice up a gin and tonic is to make your own tonic. The Conquistador is a Spanish-inspired drink with a tonic flavored with lemon and grapefruit juice, fennel seeds, cinchona bark powder (for tonic’s trademark quinine bitterness), and star anise. For the Queen Victoria, the tonic is flavored with raspberry-flavored orris root and peppery, flowery grains of paradise. Making your own tonic takes a little work, but it’s fairly easy and extremely rewarding.