If you have a base template base.html and you want to have a default title most the time, but also provide specific titles, here's one way to do it.

In your base.html, add a block named title inside of your <title> tags:

<html>
    <head>
        <title>
            {% block title %}Default Title{% endblock %}
        </title>

...

The key here is to add a default title in-between {% block title %} and {% endblock %}

Then in a template where you are extending base.html, add a title block if you want to provide a custom title.

{% extends "base.html" %}
{% block title %}Custom Title{% endblock %}

...