Ouranic deities tended to receive wine libations that were mixed with water. Khthonic deities received either wineless libations (water, milk, and honey, usually), or wine libations of unmixed wine. ‘Ouranic’ is a term that applies to Theoi and practices who reside or that are associated with Mount Olympos, home of many of the Theoi. As such, Ouranic deities are also referred to as ‘Olympians’. ‘Kthonic’ refers to deities or spirits of the Underworld or the earth, and the rituals associated with Them. Then there are some we know from the ancient writings.
So, some examples: Apollon (ouranic) recieves mixed wine libations. Gaia (kthonic, earth) recieves water libations (usually khernips), or milk, or honey. Water for the nymphs (kthonic, earth), unmixed wine to Persephone (kthonic), milk (usually kykeon) to Demeter (kthonic, earth), etc.