I'd just keep your LinkedIn profile up to date with a clear indication that you might have an interesting amount of stock (co-founder, executive, early employee, etc.) and that you're no longer with the company.
When secondary brokers have more buyers than sellers of a particular private stock, they come looking for you - and that's the time when you want to do your selling, not when people are freaking out and you're competing with others actively looking to unload their holdings.
When secondary brokers have more buyers than sellers of a particular private stock, they come looking for you - and that's the time when you want to do your selling, not when people are freaking out and you're competing with others actively looking to unload their holdings.