Add a markdown file in _posts/ folder, named by
YYYY-MM-DD-file-name.md
containing this front-matter:

---
layout: post
title: title of the post
category: jazz
tags: [ tag1, tag2 ... ]
---

This is the excerpt

This is the content
...

Optional parameters in front-matter

• class: post-class
  Is added as a css-class on your post <article> html tag. Use this to custom-style particular posts.

• description: post-description
  Used in page meta description, override site.description.

Post as headers

You can use posts just to show an header in desired position using header layout. Posts with layout not post will be ignored by archive page, search results and posts pagination:

---
layout: header
title: we love headers
---

• optional: if you need a commented header you can add a markdown excerpt below front-matter.