What template-based SEO improvements work for category pages?

Short answer: The power of template-based work is leverage: one template change touches hundreds of category pages at once. The highest-impact areas are title formulas, an editorial text slot above the product grid, breadcrumbs, internal linking modules, and structured data.

Building blocks to add

• Title and H1 formula: category name plus an intent modifier (price, model, use case), applied consistently everywhere.
• A short, category-specific intro above the grid; a deeper guide section below it.
• BreadcrumbList and ItemList structured data: the breadcrumb trail explains hierarchy to users and engines alike.
• Subcategory and related-category link modules, plus explicit pagination rules.

Roll out with measurement

A template change does not have to ship everywhere at once: apply it to one category group first, compare against a similar control group, and expand once the difference is measured. That way you learn from evidence, not guesswork, which template component actually produces the effect.