In order to make the foam rise up all the ingredients need to be cold! So make sure they stay in the fridge until you are ready to make them.
Add ingredients to tin (except Soda Water)
Add ice and Shake for 20 Seconds
Strain into chilled glass
Add Soda Water and place back in fridge for 10 minutes
Top off with a little dash of soda water and the foam will grow past the rim of the glass.
*note, try to pour in the middle to have a uniform foam head.