1. Divide William into William and surname first. You can write them as two independent signatures, which is easier to control.

2. For William's part, you can write it from bottom to top, make "W" bigger, and then write "Ilyam", in which "I" can be written smaller and slightly curved.

3. For the surname part, it can be written as a smooth curve, similar to an "S" shape, which can make the signature more unique.

You can add a small word "William" after the signature to make the signature clearer.

I hope this suggestion can help you design William's signature.