The 3 Liquids Sigil is the access key to Thee Temple ov Psychick Youth (TOPY), a group of people who chose Magick as their way of being. The Magickal World is seen as a world of total freedom, where each member is responsible for his acts. The 3 Liquids Sigil is taken as an entrance test, for newcomers to the tribe.
It is an act seen as Magickal, therefore assuring thee real commitment of each one who's willing to follow these threads.
Even if you don't intend to join TOPY, this process is very interesting, so why not try it as an experience?
It consists in writing one's desire in whatever medium the person chooses to be the appropriate material, and using the method that the person chooses to be the most appropriate to express the desire. A rather obscure method is A.O. Spare's technique for writing a desire, as quoted from his "Book of Pleasure" below:
"For the construction of Sigils the ordinary alphabet is used. The desire for super-human strength could be formulated as follows: 'I desire the strength of my tigers.' In order to Sigilise this desire, put down on a piece of paper all the letters of which the sentence is composed, omitting all repetitions. The resulting sequence of letters, IDESRTHNGOFMY, is then combined and incorporated into your Sigil. (This sequence of letters is called a glyph.) The wish, thus Sigilised, must then be forgotten; that is to say, the conscious mind must desist from thinking about it at any time other than the Magickal time, for the belief becomes true and vital by striving against it in the consciousness and by giving it (the Sigil) form."
After writing the desire, the person puts "Ov" into it. "Ov" is defined as being the semen in men, or the vaginal fluids in women. It can be seen as the source of each human to create life, and one will employ it into making the wish take shape. Each one will find the most suitable way for doing this, like masturbation, or using a partner who is also doing a Sigil or only helping you to achieve the purpose.
Blood is also given into the desire, and you can see blood as the fluid that sustains our body, that makes motion come into each person. And again each one chooses how to take his blood for the Sigil. You can cut yourself using a razor blade, or get a sample by using a hypodermic needle; witch makes it less painful and leaves almost no scars. You should use blood in any quantity you wish to use.
And finally the third liquid, saliva. Saliva also has a big importance in our life; examples can be easily given like talking, eating or kissing (a sign of love). To give even more to your desire, you could use hairs on it, from the head and pubic area. It can be seen as a "decoration" from oneself into it.
Everything is up to each individual, how to do it and when, how much liquids and ways to do sigils also changes with each individual, and each individual can change methods according to personal preferences. You may see it as an updating of the Magickal tradition, of bringing up to date things that are in each one of us, if you do choose to use them.
What happened (for me) was that things became much more intense, my life became my own responsibility, when things are bad, they are worse than before doing it, but when things are nice they are really awesome.
I think Magick is a work-in-progress, with many troubles for those involved, and the results will come according with the effort given into it.
And to finish, quoting "thee Grey Book":
"Reality falls into its place"