layout.html
<html>
<head>
<title>{% block title %}{% endblock %}</title>
</head>
<body>
{% block body %}{% endblock %}
</body>
</html>
users.html
{% extends "layout.html" %}
{% block title -%}
All Users
{%- endblock %}
{% block body %}
<ul>
{% for user in users %}
<li><a href="{{ user.url }}">{{ user.username }}</a></li>
{% endfor %}
</ul>
{% endblock %}