How to recognize the phtml file from the layout xml file ?

I want to know the proper way of identifying a template file.
For e.g.
In my basket page (cart.phtml) there is a code like...

PHP Code:

---

echo $this->getChildHtml('shipping'); 


---

I searched for the template for this as follows.....

1. I checked "checkout.xml" file for the handle <checkout_cart_index>. And find where it is written "as='shipping'" and found that code as follows...
<block type="checkout/cart_shipping" name="checkout.cart.shipping" as="shipping" template="checkout/cart/shipping.phtml"/>

2. So I checked the "checkout/cart/shipping.phtml" file and try to modify it. But nothing happend. so i confirmed that it is not the right phtml file i am looking for.

3. Then when I enable "Template Path Hints" from admin side , then came to know that it is coming from a different folder and it is due to the extension used. And in its layout file it is written as

<checkout_cart_index>
<reference name="checkout.cart">
<block type="webshopapps_productmatrix/checkout_cart_shipping" name="checkout.cart.shipping" as="shipping" template="webshopapps/productmatrix/checkout/shipping.phtml"/>
</reference>
</checkout_cart_index>

So My question is ,what is the proper way to know the template files which is used in our page as ChildHtml ?

Magento takes check folders with template files in the next order: the first place - theme from the package which is set in the admin panel, than it looks for template in the folder "default" in this package. If there is no such a file, then it should be in frontend/base/default/templates. Maybe you made a change in not right package or theme. Pls, check setting on the admin panel (system->configuration-> in tab-general click on design). Also keep attention on selected stores in the current configuration scope in the left up corner.

The xml file and structure represented by two types of hierarchy of elements that name: The attribute which is used to identify a block. public_html/vendor/magento/module-search/view/frontend/templates/form.mini.phtml.