The letter method
Write what is wanted as one sentence. The page strikes out the letters that repeat and fuses the rest into one sigil. Another gives a different figure from the same letters. Nothing written here leaves this page.
About the method
Austin Osman Spare set out this method in The Book of Pleasure (Self-Love): The Psychology of Ecstasy, which he published himself in London in 1913. A desire is written as a sentence, and the letters of that sentence, simplified, are combined into one figure. What he looked for was a form simple enough to be called up in the mind at will, and with little pictorial likeness to the desire it carries, so that the figure can hold the desire without the thinking mind taking hold of it.
His worked example is the wish for the strength of a tiger. He writes it as a sentence, draws each part of the sentence as a combined figure, joins the three into one sigil, and then gives a still simpler form of the same sigil. A note in the chapter says that the book uses six methods of sigils, that this one is the idea beneath them all, and that from it anyone can work out a system of their own.
The chapter goes on to the use of the sigil: the mind is brought to emptiness by exhausting it, in whatever way suits the person, and the figure alone is held there until it grows vague and vanishes.
Striking out the letters that repeat, and sometimes the vowels, is not in Spare's text. It became the usual practice of later writers, and the page offers each way above. The page composes the figure itself: each letter is turned, mirrored or shifted to where its strokes fall on strokes already drawn, so that shared lines are drawn once and the whole stays compact. A letter already contained in the figure, as an L inside an E, adds nothing further.
The wheel is a later practice. The alphabet is set around a circle and a single line runs from letter to letter in the order they are kept, opened by a small circle and closed by a bar, much as names were traced on the petals of the Rose. Another sets the alphabet around the circle in a different order.
Chaos magick
In the late 1970s a small circle of English writers took up Spare's letter method as a centre of what they called chaos magic, spelled chaos magick by many who practise it. Ray Sherwin's The Book of Results (1978) is given over to sigils, and Peter J. Carroll's Liber Null (1978) treats them among its techniques. These books are not in the public domain and are described here, not reproduced.
They made the reduction of the sentence into a fixed routine: the intent written out, the repeated letters struck, the remainder combined. To it they joined the charging of the sigil in a state of emptied or heightened mind they called gnosis, after which the sigil is deliberately forgotten.