[wilwade]

A few things I haven't seen mentioned.

Make sure you have connections with your coworkers you wish to remain connected with (for friendship and/or opportunities).

Make sure you have no personal data saved only on your work computer.

Advocate for open sourcing any small utilities or other code that you have written so that you can have good public code samples.

Make sure that you have non-work access to retirement accounts, paycheck stubs, etc...

Finally, be willing to leave first. (For many) it can be hard to not have your work as part of your identity. Remember that businesses cannot care about you, just people in them.