How did you start your own Private Label?

I know it’s going to be a lot of work, but I am working on setting up a private label to sell in Amazon FBA.

That being said, what kind of strategy do you recommend? I plan on selling products in several categories. Do I start by trade marking my brand? If so, whats next? Once I have a brand and trademark, what do I have to communicate with the manufacturer? Do I send them the design of the stickers I want to put on my product? Am I missing anything? How did you brand your products? Any advice or suggestions would be so appreciated. I am committed to this business!