WordPress.org

The template management page (From here, create template, create a post from a template, ...)

The template edition page (From here, edit your template and create a post from this template)

The post management page (You can create a template from an existing post using the "Templatize" button)

The post edition page (You can create a template from current post using the related links)

Support of custom fields (since version 4.0.0)