Some co-workers were talking today about how one of their children had been caught forging their parents signature. This reminded me that I started doing this in the 7th grade, I had two techniques.
The first, was to get my mom to sign something, take tracing paper and trace over her signature with a heavy pen. Then I would turn it over and rub a pencil all over the back. Then when I needed my Mom's signature, I would just put my tracing paper on the line, and trace over the signature, this would leave a light pencil trace on the line, where I would once again go over it with pen. Worked like a charm.
The second method was to simply sign my Fathers name to whatever needed signing. Since I was always the one signing it, they could compare it all day long and it would always be the same. When someone would ask me saying, I thought your Father did not live in the house and your parents were divorced, I would simply say, yes, that is true, but I am staying with him for a couple of weeks. No one ever questioned me about it.