Prep your glass by making the cucumber ribbon garnish. Use a peeler (or sharp knife) to shave off a long slice of cucumber, at least a couple millimeters thick. Carefully wrap the cucumber slice around the inside of your glass, starting at the bottom and slowly turning the glass as the cucumber slice spirals upward. If it helps, use a spoon to press the cucumber against the inside of the glass, using its own moisture as an adhesive. Cut off any extra cucumber. Note: the slice should not be paper-thin, as it will need to hold firm as you wrap it around the inside of your glass. Cut a thicker slice if needed.