Anuyoga

Anuyoga (Skt. अनुयोग 'further yoga') is the designation of the second of the three Inner Tantras according to the ninefold division of practice used by the Nyingma school of Tibetan Buddhism. As with the other yanas, Anuyoga represents both a scriptural division as well as a specific emphasis of both view and practice.

Anuyoga is said to emphasise the completion stage of Tantra, where the preceding division, Mahayoga emphasises the generation stage. Dalton (2003: unpaginated) in introducing the literature of the Anuyoga-yana affirms the affiliation of the Anuyoga-yana with the 'completion stage' or the 'perfection stage':

Modern-day doxographical presentations of the Nyingma school are usually based on the system of the nine vehicles (theg pa dgu). Emphasis is placed on the highest three vehicles in this scheme, namely Mahāyoga, Anuyoga, and Atiyoga. Generally speaking, these three “inner” yogas correspond to three stages in tantric practice, namely the generation stage, during which the details of the visualizations are stabilised, the perfection stage, in which those visualizations are then employed towards familiarizing oneself with the state of enlightenment, and finally the Great Perfection, the spontaneous accomplishment of buddhahood. Being the second of the three inner yogas, Anuyoga is thus associated with the practices of the perfection stage.

Ray (2002: p. 124-125) mentions visualization, subtle body, chakra, prana, nadis, bindu and pure land:

Anuyoga-yana is associated with the feminine principle and is for those whose principal obstacle is passion. In anuyoga the emphasis shifts away from external visualization toward the completion stage, in which one meditates on the inner or subtle body with its primary energy centres (chakras), and its prana (winds or subtle energies), nadis (the inner pathways along which one's energy travels), and bindu (the consciousness). In anuyoga, all appearances are seen as the three great mandalas, and reality is understood as the deities and their pure lands.

...
Wikipedia