What are your best tips for a successful pre-launch campaign?

Hi everyone, My name is Sonia and I'm the CEO and Founder of Outset Wellness (https://www.outsetwellness.com/), a company which focuses on helping people form healthy habits to solve one of the greatest challenges of our time: physical inactivity. We're finishing our build and aim to launch to the public in late May. As many here, we're also entirely bootstrapped, so if you have any tips/lessons learnt on how to build a successful pre-launch and launch campaign, please share them - I'd greatly appreciate any insight. Bw, Sonia