The Blue Lotus (Nymphaea Caerulea) herbs should be soaked in the alcohol for at least 2 hours, but can be kept in it up to one week or more, depending on how strong you would like to have your drink.
You can use almost all alcoholic beverages to mix with Blue Lily, but strong alcohol is recommended.
You can also smoke a joint of the dried herbs in while drinking the liquor, it will surely increase the effects.