Sigil magick is based on the idea that magick is largely your subconscious at work. A sigil is made, charged, and submitted to your inner psyche for processing. It's a fairly simple working; the hardest part is charging the sigil.|
First, write a statement of your intent. Something like this: "I will lose five pounds." Try to make it as assertive as possible (ie "I will" instead of "I want to").
Now you can do one of two things, or both, whichever you want. Eliminate all the repeating letters, so it reads "I wl ose fv pund." You can also eliminate the vowels if you want, making it "Wlsfvpnd." I find it easiest to do both (fewer letters to work with).
Now, make a sigil with your letters. This can be anything. Arrange the letters any way you want; just make sure they can't be recognized as the original statement.
Now for the hard part: charging your sigil. There are several methods you can use. First, stare at your sigil for a while, focusing all your attention on it. Don't think about your intent; you don't have to do that, because it's all put in the sigil. Then when you're ready, start charging! You can do it any way you want: sexual energy (I hope we all know what that is!), fear, love, anger, pain, whatever. WikiHow describes charging a sigil as: Charge the Sigil having it in your mind during an altered state of consciousness. You can use Any means to achieve this altered state such as, Meditation, Dancing, Sexual release, Skydiving, fighting, Chanting, Yoga, Ritual, Etc.
Now that you've charged it, forget everything. That's right: erase the sigil from your mind. It doesn't matter if you remember that you did a working, or what the working was for; just forget the actual sigil. This is because a big idea in chaos magick is that lust for results screws around with the natural course of the magick. Another important thing: if you're trying to lose five pounds, don't stop dieting just because you did the working. This also messes up what might happen naturally.
If it doesn't work the first time, try again! It's important to experiment when doing chaos magick. If this doesn't work for you, make up your own thing.