Great question. Post-launch is the most underrated parts of the cycle. You've spent months aiming the rocketship, putting fuel in the tank and blasting off - now you've got to steer. Let's break it down into three steps:
The first thing is to immediately begin watching not just usage of the product, but which parts of the product. How are people interacting with your features? Where are they dropping off? Where are they spending their time? This will give you context and clarity to move onto step two.
Now that you know where your hypothesis was roughly right or wrong, develop a plan to go after those areas. Our team uses a one-pager that is incredibly simple, laying out the problem we're trying to solve (ex: the pricing is too high, awareness is too low) and mapping out in specific detail, right down to the deliverable specs, how we plan to solve it.
Especially soon after launch, when blemishes become clearer in the light of mass user feedback, we aim to move quickly. If you're still talking about a major problem with the way the product has been positioned or messaged two weeks later it's been way too long. Standups with your cross-functional team including creative shouldn't end at launch! The fun is just beginning...