Severance offer, what should I ask for? - what worked for you?

I was offered 11 weeks of severance after 11 years as a machine operator, and I have a few days to sign. I worked as a machine operator before this. I do not want to leave money on the table.

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.