How to add breadcrumbs on custom phtml page?

You can add breadcrumbs from your custom index controller action. Reference code is below.

<?php 

 
    public function IndexAction() {     
      $this->loadLayout();
      $this->getLayout()->getBlock("head")->setTitle($this->__("CB Magento Developer"));  /* add your page title */
            $breadcrumbs = $this->getLayout()->getBlock("breadcrumbs");
      $breadcrumbs->addCrumb("home", array(
                "label" => $this->__("Home Page"),
                "title" => $this->__("Home Page"),
                "link"  => Mage::getBaseUrl()
           ));

      $breadcrumbs->addCrumb("magento_developer", array(       /* add css class */
                "label" => $this->__("Magento Developer"),
                "title" => $this->__("Magento Developer")
           ));

      $this->renderLayout();

    }

?>

How to add breadcrumbs in Magento.

You have add bredcum by two ways:

1. Via code (Add in a controller):

              $crumbs = Mage::app()->getLayout->getBlock('breadcrumbs');

           $crumbs->addCrumb('home', array(

'label' => 'Home',

'title' => 'Go to Home Page',

'link' => Mage::getUrl('')

));

2. Via Layout XML:

              <reference name="breadcrumbs">

                 <action method="addCrumb">

                     <crumbname>home</crumbname>  <!-- Class Name Which apply on li -->

                    <crumbinfo>

                         <label>Home</label>

                        <title>Go to Home Page</title>

                        <link>/</link>

                  </crumbinfo>

             </action>

            <action method="addCrumb">

 <crumbName>cb</crumbName>  <!-- Class Name Which apply on li -->

<crumbInfo>

<label>CB</label>

<title>CB</title>

</crumbInfo>

  </action>

</reference>