This is a pretty simple little snippet and this is how I have the breadcrumbs working on this site. (Not sure why I didn’t post this sooner)

hints/view_hint.html

{% extends 'base/hints.html' %}

{% block breadcrumbs %}
    {{ block.super }} »
    <a href="{{ hint.get_absolute_url }}">{{ hint.title }}</a>
{% endblock %}

base/hints.html

{% extends 'base/base.html' %}

{% block breadcrumbs %}
    {{ block.super }} &raquo;
    <a href="{% url hints_index %}">Hints &amp; Tips</a>
{% endblock %}

base/base.html

{% block breadcrumbs %}<a href="{% url home %}">Home</a>{% endblock %}

Using block.super we can also display the contents of the block from the parent file. Each file in the chain adds to the existing breadcrumb block, we just work our way up through each of the sections.