Sacrificium e Sacrificare mean "making sacred" or making a translation into the divine dimension and opening a link with the divine sphere. The central core of a sacrifice is the execution of a rite through which, with an offer, the destruction of dissolution of something is made in relation with an invisible entity.
According to Ovid, the term libatio derives from Liber or Dionysus: this God brought libatio as a tradition coming from the Vedas of Ancient India. Libamina are the offerings in the libatio. They are, in order of importance: wine (an offer from a plant), milk (an offer from an animal), water (an offer from Mother Earth). Nonetheless other kind of libamina (food, seeds, etc.) can be offered.
Libatio is a form of private sacrifice thus expressing a dissolution, "a destruction in order to have something". The most common gesture in a libatio is the pouring of a liquid into the fire or on the ground.
Any moment of the day may be good (fas) to make a libatio, but the main libationes are those of the morning and those of the evening (libatio before sleeping and libatio when the sacred light comes back). the normal everyday life can be considered as such (it means: sacred) when included, through a circular movement, between these two polarizing acts.
A libatio, according to the ancient rite deriving from the Vedas heritage, can be made pouring four spoons of milk (wine or water) into a bigger spoon and from this pouring milk into the fire or on the ground (twice). A kind of simpler libatio involves the pouring of four spoods of milk (or wine or water) into a bowl and, with a well stretched (left) arm, from this pouring milk (wine or water) on the ground (twice). Please remeber that during a libatio it's better not to hold iron objects or knots.
A libatio with water always implies a purification rite.
More complex rites or those involving important moments of a family life or the consacration of a site may imply more complex libationes: a libatio with wine first, then with milk and finally with water.
The ancient rite, deriving from the Vedas tradition, implies this formula: "the God/Goddess who draws this libatio, being grabbed by this libatio, take-support-fulfil the desire for which he/she draws it"
Please note that this formula, like others, can be expressed in silence, murmured or expressed aloud: there are great differences in this (mens and vox) I'll describe in the future.
From this, it is clear enough that libatio is an instrumental rite in order to create and have the support of the divine during the day course or during the making of some acts.