I replaced nearly every letter in the alphabet (k was redundant) with a symbol that can be written quickly and simply.
In order to create the greatest efficiency the most commonly used letters, like the vowels have the simplest symbol to replace them, in order to speed the writing. Also all of the symbols were chosen to ensure that the pencil always moved forward and never backward, which would be a waste of motion. (j, x, and c were the exceptions)
I use this shorthand system now in conjunction with the normal alphabet until I am better aquainted with my own creation. Once I have practiced enough, the mechanics of the letters will speed my writing significantly. It will also keep people from asking to use my notes.