A lot of this will come off as common sense, but here's my take as someone affected by a RIF.
Regardless of your situation, do the job you're paid to do. That being said, I would recommend not doing an ounce more than your core responsibilities nor go out of your way for the company that deems you expendable.
Regardless, help your fellow co workers as usual, but do not do their work for them. If you have a good relationship with your current supervisor/manager/director, remember that they will be also tasked with dealing with the aftermath of your absence/departure and the time leading up to it. If you have a rocky relationship with them, you can remind them what your duties are but don't give them a reason to put another target on you.
Everyone that has worked for 10+ years with the company (whether union/non-union, Landline, Wireless, other) knows how to sham off and become invisible if you have to (just follow what others have done in the past). If you do go this route, know your audience and know that it will upset those that are staying behind. No one can make that decision for you as to your choice of doing actual work or slacking off. Around 70% of the time, it's better to go out like a professional, rather than a leech. If you want to start the slacking off, wait until after the release date.
If you have personal commitments, do what you need to do. With that being said, NEVER throw those that have helped you along the way under the bus. If you feel that urge to be bitter, do something to release that anger or frustration outside of work. It is very hard to understand the details of this transitional period, but also know that it's human nature to be extremely frustratred because of this.
Great post by @WwU93JT-1xdd on another thread. This is good advice.