How do you add friction to your signup flow without killing conversion rates?

It's so tempting to keep the front door wide open so anyone can jump in and try your app in two clicks. The downside is that you end up with hundreds of random signups who churn instantly because your product doesn't fit their actual workflow.

We started adding a quick two question onboarding survey just to understand who they are and it surprisingly scared away a lot of the bad-fit traffic.

What specific qualification steps or friction points did you add to your signup process to protect your product roadmap from the wrong feedback?