1. Login to blogger.com
2. Design --> Edit HTML --> (download a backup of your Template). Find this code snippet :
<b:include data='post' name='comments'/>

and replace with this code :
<b:if cond='data:post.showThreadedComments'>
<b:include data='post' name='threaded_comments'/>
<b:else/>
<b:include data='post' name='comments'/>
</b:if>

Check in preview your blog.


If that too doesn’t work
1. Make sure that you have enabled Comment Feeds
2. Check and Use the Embedded Comment Form.

Enjoy
1. Login in to blogger.com
2. Go to Layout --> edit HTML in your Blogger dashboard.
3. Search for this tag: <title><data:blog.pageTitle/></title>
4. Replace this tag with the following code:

<b:if cond='data:blog.pageType == &quot;index&quot;'>
<title><data:blog.title/></title>
<b:else/>
<title><data:blog.pageName/> | <data:blog.title/></title>
 </b:if>

5. Save your template.
1. Login with your blogger account
2. Go to Blogger Dashboard --> Design --> Edit HTML
    and click on the button which says “Expand widget Templates”.
3. find </head> and immediately above that paste
<script type="text/javascript" src="http://apis.google.com/js/plusone.js">
{lang: 'en-US'}
</script>

5. Now find <data:post.body/> and immediately below that paste
<div>
<g:plusone size="standard" expr:href="data:post.canonicalUrl"/>
</div>

6.Save the template.