Start with a big glass, one with a wide opening to allow the nose to take in all the flavours. For instance a red wine glass otherwise a highball glass will work. It's important to get the temperature of your glass right. It needs to be cold, so add as much ice as you can. Above all, you need to get the measurements right. 50ml of gin and 150ml of tonic is ideal but you can push it to 200ml if you like a longer drink. As for garnishing, you can't go wrong with just a simple classic lime wedge. If you fancy something with a bit of spicy try orange peel and star anise. A firm favourite of ours is sliced cucumber and fresh blueberries, especially on a summers evening.