Celebrating the final chapter of someone's career usually takes one of two forms: nostalgic tribute or good old-fashioned roast. Consider the person you're toasting and the intended audience before you decide which way to go. Since toasts to retirees tend to be on the long side (they can, after all, span decades of work and last up to 5 or 10 minutes), make sure you're prepared. Rehearse and carry note cards, just in case.