So having connected and united with the Guru, one should sit confidently as such for sometime. The initial visualization/feeling should correspond to one's Guru as one knows them (i.e. appear/feel in a way that is most familiar). The activity meditations can be done as a group or individually as one sees fit. There are corresponding short bija mantra with each activity, but that portion will not be inculded here. However, it should be noted that when using the mantras, they are not chanted like one's normal japa, but take on different patterns (like slow/long/pervasive in style or like a swarm or like a swarm inside something pervasive etc.) depending both upon the activity and the particular point in the meditation. Also, it should be noted that the bijas can be used as part of the visualization process. That said, one can do the sadhana without the mantras, and in many cases, doing so can actually be more beneficial (in that one can just focus on points of sincerity).
With the first kriya, one should think of themselves as the Guru of pure white color, youthful and wearing jewel ornaments. The eyes are half open, and the bhava is gentle and filled with love and kindness. After sitting in this mood sometime, one should identify aspects of their conventional self or energy that is not in accord, and then as the Guru (from the heart center) pour white light/energy into those areas. One should feel those areas flooded with love and feel the energy liberate into deep accord. (One can easily be stationed as the Guru in the practice while still identifying aspect of self.) Next, one should extend that white light through the universe and all realms of existence. The understanding should be that the fundamental nature (which one is sitting as) is pervasive and without obstruction, so the expansion of the white light is contained in the understanding and doesn't involve "stretching" but rather relaxing into . One should feel that this light is touching all beings and giving great peace to all. One should think that it is easing all suffering and that all beings are filled with that love. Finally, one should feel that all that are touched by this light are liberated. One may do this kriya in a broad way or do in a way which focuses on each realm of samsara individually. It is also important to understand that one is sitting outside of time, so these kriyas permeate beings of all times.
Sit as the Guru with red or pinkish complexion, with a smile/smirk, this form should be seen as attractive and playful. Even if one's Guru is male, this rupa should have some almost feminine characteristics (like krishna is depicted sometimes). One should think that a whole retinue of beings (devatas, yoginis, protectors etc.) surround and have love for you as this form. Bringing the conventional self/energy before this manifestation, look for areas not in accord. One should regard any heavy energy laden with self-pity and "hard luck" narratives, and also bored/resigned energy (same shit different day type narratives), and pour red light into it. After bringing accord, one should proceed to either fill the realms of existence with that light or see a myriad of red yoginis filling existence and touching all beings. One should feel that as this light (or yoginis) permeate beings, that spontaneous blessings and empowerments come to them, and they are drawn immediately to the path and are liberated. One should feel all these beings joy, and feel joy in it.
With a stern disposition, sit as the Guru with great command and power, the color of yellow and difficult to approach as the power of this forms presence has a great weight that projects (like the gravity force becomes too much for anyone to navigate). One's bhava should be fearless and assured. When bringing forth one's conventional self/energy, look toward restless places of avoidance as well of points of the habitual tendency to cling to thought, and bring these elements into accord with the force of this Guru presence while bathing in yellow light. When using forceful kriyas to benefit beings, it can be useful to do so on a collective aggregate of qualities. Therefore, one can either proceed as in the former kriyas, by this time sending a yellow light or yellow yoginis holding clubs to permeate the realms (and all times) of existence stoping the suffering and various afflictions of beings (and thus liberating them) or invoke and "personify" those afflictions. In the later case, one should regard the suffering and affliction of beings as a demon type hoard that at first looks strong and confident. But as you (in Guru form) regard them with unmoving confidence they become terrified, and as the light or swarm of yoginis hits, they are stunned and fall down unable to move. When that happens, feel that beings are freed from those delusions and are liberated.
From uncontrived spacious awareness, assume the form of the great wrathful Guru who is dark blue in color, with fangs dripping blood and adorned with skulls and serpents. Standing in a great cremation ground surrounded by a sea of blood, you hold a skull cup with a gaze of intense lightening. The bhava is very fierce compassion. It should be understood that the more fierce the manifestation, the more deep the compassion must be. In fact, it is only through deep compassion that one can truly manifest a wrathful form, as otherwise it is just an expression of anger or frustration that cannot reach the proper intensity. In this form, you are keen to act, like a parent seeing their child in danger or suffering. Bringing forth the convention self/energy, be keen to recognize the aspects not in accord, particularly see the incursions that you've taken on yourself ranging from other peoples views, culture, expectations, negativity, projections etc., and then see the biggest incursion of self grasping and "personhood". With wrathful expressions, one may find another element that is not in accord which can be broadly defined as sentimentality. People often confuse it with compassion but it is actually being sentimental for samsara (and the experience of it and people in it). Encountering ruthless expression of reality are good for exposing and confronting those places in us. The broader kriya can be done as in either manner described above, however in this practice the light/yoginis are dark blue (with the yoginis holding swords) and the obstructors are completely driven away in terror. The energy moves like a great hurricane that nothing can stand against. With great sincerity and intensity, liberate beings with this manifestation.
Standing upon space/time, take up the extremely wrathful presence of the Guru who is black in color with a great fire surrounding. Wearing a crown of skulls and bearing fangs, one should see themselves as holding daggers in each hand and wearing a mala of skulls. With eyes wide and blood shot with intensity, bringing forth one's conventional self/energy, one should see that accord or non accord don't matter, and with a gaze one and all identification is dissolved. In this form, one should shake all of the realms of existence like a cosmic scale "earth quake", and dance throughout the realms. With a great laugh, the roots of delusion are seen as completely empty. As one dances, the roots of ignorance are utterly destroyed, and everything dissolves into the dance itself. Having dissolved everything, when finished with the sadhana view what appears as all expressions of the pure nature and let everything encountered point back to that rather than obscure it.
Contained in these practices are several layers of understanding which open up to one upon sincerely encountering them. The practices allow one to connect with their Guru in a deeper way, while not only removing obstacles for themselves, but also acting for the benefit of all. Since one's nature is primordially pure, all real practices are mainly about removing obstructions to realizing it. Those with some knowledge of Tantra may see that the activities given correspond to five of the so called "six rites". However, while many "tantrics" nowadays view and use the rites for stupid and mundane purposes, one should understand there true import. The only meaning in this life is our own (enlightened) view and how much we love. When you meet death, that'll be all that matters. Don't have any regrets.