Five high-value types: WebSite with SearchAction, Organization or Person for brand identity, BreadcrumbList on every inner page, Article/BlogPosting on posts, and Product on commerce pages.
Use @id URLs consistently across emissions — {home_url}#organization, {home_url}#website, {post_url}#article. Google’s Rich Results Test validates the output.
Avoid stuffing irrelevant types. Schema rewards accuracy; over-marking gets devalued.