Baby boomers don't like to think about exit strategies. We want to live forever. However, one thing that I would recommend is that you know the date that you want to leave the company. And during the last three years of that time, use your time to mentor your replacement.
Of course, by that time, you would have already negotiated your parachute or the retirement plan. And while you won't be an ongoing partner, you could act as a consultant to the company until there is a smooth transition.
What you should do
But know the date when you want to leave. Try to plan accordingly by mentoring a replacement person and of course consider acting as a consultant. And every year, look at your retirement package and make sure that it is substantial enough to sustain you during this well-deserved time called “retirement.”