Should I negotiate my severance? - what worked for you?

I was offered 11 weeks of severance after 11 years as an electrician's helper, and I have a few days to sign. I worked as an electrician's helper before this. I do not want to leave money on the table. What did you ask for?

I asked for two more weeks and a neutral reference. They agreed to the reference and added a week.

An hour with an employment lawyer cost me a small fee and made me feel much safer about signing.