If you know that you are going to want to sell your business you need to start having that conversation with your business advisor and/or accountant at least 2-4 years before you want to sell.
As it takes on average between 6-12 months to actually sell a business, this allows you plenty of time to make sure you get the best possible payout.
You need to develop a plan to add value to your company, so what kind of things will make up this plan?

Things to consider when setting up a Business Exit Strategy

Keeping Financial Records current & up to date
Reviewing contracts