Edit product-list.tpl file, which is located at PrestaShop's themes directory:
Find product image (image begins with<img and ends with/> this is how it looks line in default prestashop theme)
After
<img src="{$link->getImageLink($product.link_rewrite, $product.id_image,
'home')}" alt="{$product.legend|escape:'htmlall':'UTF-8'}" {if
isset($homeSize)} width="{$homeSize.width}"
height="{$homeSize.height}"{/if} />{if isset($product.new) && $product.new == 1}<span class="new">{l s='New'}</span>{/if}
add this line: (after {/if} and before </a>)
{include file=$smarty.const._PS_MODULE_DIR_|cat:'labels/ribbon.tpl' id_product=$product.id_product}
Edit homefeatured.tpl file,
which is located at modules/homefeatured directory if you wish labels to be displayed in featured products module on your homepage (Featured Products on the homepage module must be installed
Find product image (image begins with <img and ends with /> this is how it looks line in default prestashop theme
<img src="{$link->getImageLink($product.link_rewrite, $product.id_image,
'home')}" height="{$homeSize.height}" width="{$homeSize.width}"
alt="{$product.name|escape:html:'UTF-8'}" />
After add this line: (after /> and before {if})
{include file=$smarty.const._PS_MODULE_DIR_|cat:'labels/ribbon.tpl' id_product=$product.id_product}.