You may be employed in a company where there are no options for negotiations but it is definitely worth trying to push for more rather than take the first offer which is presented.
Negotiations should be undertaken in a calm situation, this will be a very stressful time therefore if you believe that redundancy offers are on the cards you will need to be one step ahead. You will need to think about what you are going to say if you receive the call to the office. Points to bring up can include
Your contributions to the company and how those should be taken into consideration.
Be aware of what your retirement plan would have offered if it had come to maturity
Your years of loyalty
If you have made significant sales in the past it might be a good time to remind the person who is making the offer of that fact.
It is always worth remembering that in the first round of redundancy offers that these are always the most munificent, subsequent offers are frequently less generous. So if you think that you are in the market for a change of career, plan for it and if the option is offered you can take it first time round.