I made a bottle of soda using this as my basis, when I did it I forgot the recipe so did it from memory and it was a bit ad-hoc and based around both recipes
3 cups (mug size) of water
2 cups (mug size) of sugar
big bunch of lemon verbena
Add sugar and water to pan and boil until disolved, add lemon verbena and keep stiring until reduced to quarter. Take off heat and fish out lemon verbna and add to a bottle (watch your fingers) then pour syryp into bottle and cap.
Store for a few weeks some place dark and cool and keep shaking it every now again. After that it's ready to use and you can at this point either.
Add vodka and repeat storeage and shake for two more weeks or use stright away adding to soda and ice.