I have to make a retirement cake for a coworker for Thursday and I just can't think of what to put for a message. I tried asking some of my coworkers but all I got was let the fun begin.
Enjoy your retirement
Best wishes on your retirement
I tend to go with the obvious!
If there is something they are going to be doing - like traveling slant the message to that.
Have fun ________.
Depending on what they are retiring from you could go w/something like: NO more _______.
She's retiring early because her husband is having health problems.
Then how about just
We'll Miss You
and / or
Best Wishes for The Future[i]