Those who are proficient in kabbala are able to consciously channel G‑d's blessing and beneficence into the world. This is achieved through the process of kavana, "intention," (pl. kavanot) - kabbalistically formulated meditations used during prayer or while fulfilling a mitzva. It is through kavana that the sefirot become properly harmonized and united, allowing the Divine efflux to flow down, and the soul of the person practicing the kavana (called a "mechaven") becomes a channel through which G‑d pours out His benevolence.

He becomes the abode of the Shechina

When the mechaven cleaves to his Creator in thought and in deed (by fulfilling the mitzvot) his soul rises up and is elevated from level to level, from principle to principle and from cause to cause, until He pours out upon him a great outflow of beneficence so that eventually this righteous person can become the seat and locus of outflow for the entire world. He becomes the abode of the Shechina and the node through which G‑d's blessing issues forth to the world. The mechaven therefore bears great responsibility towards his fellow man; at the same time, he is a greatly privileged individual.

When meditating, the mechaven does not focus on the sefirot per se, but rather on the atzmut (the Infinite Light) illuminating the sefirot - his prayer is "to Him, not to His attributes."(Sifri) Proper kavana focuses upon G‑d as He is when acting through the sefira of chesed, for example, or through gevura. The Essential Name of G‑d represented by the four letter Tetragrammaton - Yud-Hei-Vav-Hei, is indicative of the Infinite Light clothed within the sefirot. Each sefira is distinguished from the others by the manner in which the Infinite Light is clothed within it. This is indicated by the change in the vowel-points (nekudot) found underneath each of the four letters of the Name in each sefira.(Pardes Rimonim sha'ar 32, chaps. 1-3)

Each sefira is distinguished by the manner in which the Infinite Light is clothed within it.
No vowels

One who is versed in kabbala knows how to act at the right time by knowing which sefira dominates at a particular time, and he cleaves to the light of the dominant sefira. He can then bring about the correct adjustment and harmonization of the sefirot through proper thought, speech and deed. In this way a person extricates himself from lack of awareness of G‑d, which may be compared to sleep and death, and binds himself to holiness and eternal life, which is the mystery of Gan Eden. Thus the Crown of the Shechina never departs from his head.

[Translation and commentary by Moshe Miller from Tomer Devorah chap. 10.]