1: Pick one letter of the longest form of your first name.
2: If it’s a consonant, replace it with any other consonant.
3(a): If it’s a vowel, and you are evil, replace it with y.
3(b): If you are very evil, rearrange all the letters to make it sound as evil as possible.
3(c): If it’s a vowel and you are not evil, replace it with any other vowel.
4: If you are not evil, you can shorten the name. If the shortened form is the same as the shortened form of your real name, tough luck.