1 part of soda water
1 part of Orange Juice
ice cubes (or ice)
1 part of Heering Cherry Liqueur (or cherry liqueur)
There are many good cherry liqueurs you can use, but I prefer Heering. Add one share of the liqueur. Then you add one share of Soda. For a sour sling use Tonic (most people prefer the drink without Tonic). Afterwards you fill the glass with Orange Juice and ice cubes.