Usually however there is a problem with the love potion in that it makes the person who drinks the love potion fall in love with the very next person they see. The other problem is of course getting the person to drink the love potion.
Some love potions are simply herbal or aphrodisiac recipes.
Usually some sort of incanation is performed as part of the process of making the love potion. Some potions are made so that the practitioner drinks the love potion. Usually the practitioner wraps locks of the intended persons hair around their fingers. The most potent love potion I have seen is that used by the Tamar where simple fresh stream water is used in an elaborate ritual which gives the potion its power. In fact this potion has never failed.