Is there a way to create scratch orgs that have the same metadata and schema as the production org?

While using Salesforce DX to develop components like Page Layouts, it becomes instantly clear that a baseline scratch org won't work all that well since they do not include layout customizations and added/removed fields.

If one cannot create a scratch org mimicking the production org, how does one make sure that components, such as Page Layouts, don't overwrite existing customizations?