The goal is to link the sigil to a specific energy so nobody else can hack it. There could be millions of thoughtforms who think/say they’re the demon Belial, but there’s only ONE specific energy that you’re aiming for. If you’re making the sigil manually using a particular method, you will have to link it to the energy you want manually and reinforce that link overtime.
In my experience, channeled sigils work a lot better since you have that energy flowing through you at the time you produce the sigil and anything written created while possessed/channeling tends to retain the energy and mental state you were in when you produced it, and coming back in contact with that will tend to automatically bring you back to the energy and mental state you were in at the time. This is the reason why great writers have such a hypnotic quality to them, because their words are infused with the state they were in when they wrote it and automatically pull receptive people right in to the same place.