You just need a blender, some peeled lemons, mint, sugar, and ginger. (Ginger is important.)
Put the lemons, mint, ginger and sugar in the blender. Add water to the top of the blender.
I will tell you what the quantity I used.
2 big lemons or 6 small
A small piece of ginger. (Not a whole one, Don't put too much ginger)
Mint (I used a fresh plant so I put 5-6 stems with green mint on them)
Done! Don't forget to put ice cubes to enjoy it in the hot summer times.