I did a lot of research on this issue, and it seems that one thing is clear: magics and religion uses drawings which are clearly depending on using precise geometry rules.
We see this in movies, in anime, in all known religions which use symbols...
The most basic shape is straight line. This is also one of Nordic symbols for protection: I
The second basic shape are two lines. This is usually either X, either cross.
X is another nordic symbol, while cross is a Christian symbol.
Then there are 3 lines, which is a triangle. Triangle in reiki is a symbol of fire, or if turned upside down, then symbol of water.
A square has an entire series of magic related to it, even many books written about it. There are word squares and letter squares commonly used not only in magic, but as puzzles in problem solving.
A circle is an obvious one, used in magic often.
Pentagram is another obvious one, usually related to satanism. However, an incomplete pentagram is also used in satanism. An incomplete pentagram is pentagram where bottom line of pentagram is missing, so it essentially only has 4 lines which form a symbol.
Octagram is less known, but actually, octagram is a very powerful magic symbol. Drawing circle and octagram inside it, and message in octagram would likely produce a powerful magic effect.
But now we come to an entirely new area, and that is combining symbols. For example, you can combine square and circle by placing square inside circle or circle inside square.
So how does all this work?
Its more simple than it sounds.
The goal is simply to combine words or letters, shapes from geometry and intention. The goal is that you have lines which connect words in multiple ways to form same message in each way. So the goal is to create consistency, an equality, which is crucial.
For example, in case of cross, you would write your request two times, once on each of two lines on a cross.
In square, you would normally divide square on 16 equal squares. And in those squares, you would write words or letters so that no matter which way is it read, the message ends up being equal.
What I see in magic sometimes are undefined shapes. These are usually shapes which dont follow usual geometry shapes. I consider these to be good as well, but they are more difficult to work with, and its more difficult to figure out how to combine them with words.
Usually, the goal is that lines in shape connect words to form a message. With undefined shapes, this is more difficult because lines must follow consistent rules of connecting words, the connection line must be same, otherwise message could get mixed up, and rule of consistency of message wouldnt apply.
