What are the hygiene factors to convert relevant organic web traffic to users?

Focus on your product funnel and make it as easy as possible for your web traffic users to move through the "funnel" Sometimes it's better to "show than tell" so you'll have to monitor how a user interacts (something like Hotjar will help). After that, UX principles come into play and you can sort of guide them through their journey

Make the registration process easy. So you don't lose your users during the registration process. Sign in with Apple, Google and FB could also be helpful.