Wash a lemon and wipe off the water on the surface.
Take away the lemon peel (be careful not to take away the white part)
Cut it into thin strips (I took the whole shape with a paring knife, so I'm going to cut it smaller)
Take out coarse and fine granulated sugar for later use (other granulated sugar and salt can also be used).
Take 80g of coarse sugar and 80g of fine sugar respectively, mix them with the leftover of half lemon peel, and put them in a jar for sealed storage.
Shake it every day to prevent the sugar from caking completely (during which the lemon peel will be marinated with a little water) and marinate for 3-5 days.