Here is a quick easy-to-understand tutorial on how do it to every blog posts and even to those old published posts.
Note:
Before you can add in your signature, logo or tagline, you need to create the image which you like to add to your blog post.
Then you have to upload it to image hosting sites like: Image Shack, Photobucket, TinyPic, Flickr, etc.
From there you can get the image URL, which you need to add to Blogger.
Method: 1
1. Go to your Blogger Dashboard.
2. Click on Theme then click on Edit HTML.
3. Now look for this line of code:
post-footer-line post-footer-line-1
How To Find:Press on CTRL and F together. A blank space with the word Search: will appear at the right top corner of the HTML box.
4. Paste post-footer-line post-footer-line-1 in the blank space.
5. Press on the Enter key.
6. Instantly you will see the highlighted code post-footer-line post-footer-line-1.
Note: Some of you may see your code as this:
<p class='post-footer-line post-footer-line-1>
Don't worry. It is the same thing.7. Now paste the image URL right BELOW post-footer-line post-footer-line-1
8. This is how to write the code:
<center><img src="image URL"></center>
9. Click Preview Template.10. If it is fine, then click Save template button.
That's all.
Method 2:
Similarly you need to create an image and upload it to image hosting sites as mentioned above.
1. Go to your Blogger Dashboard.
2. Click on Template then click on Customize button.
3. Click on Advanced.
4. Pull down the vertical slider until you see Add CSS.
5. Click on Add CSS.
6. Paste the code below inside the blank box on the right side of the page.
.entry-content:after {
content: YOUR-IMAGE-URL-HERE;
margin-left: 200px;
}
Note: You need to replace the YOUR-IMAGE-URL-HERE (highlighted in white) with the url of your image which you have uploaded to image hosting site. content: YOUR-IMAGE-URL-HERE;
margin-left: 200px;
}
You may need to change the number 200 to be higher or lower, depending on whether you want your custom icon aligned left or centered.
7. Once you are satisfied with the positioning of your icon, click on Apply to Blog button located at the top right hand corner.
That's all you need to do.