There are a few methods you can use to create a favicon for your blog. You can use an online service, or you can create your own using an image editing program.
One option is to use an online service like Faviconize.com.
This site allows you to upload an image of your choosing, and then provides a custom favicon for your blog. This favicon will appear in the address bar of all browsers when users visit your blog, and it will also be shown in the Chrome Web Store.
Image Editing Programs:
If you don’t have access to an online service, or you want to create a more customized favicon, you can use an image editing program like Adobe Photoshop or GIMP. Once you have your image prepared, you’ll need to convert it to a favicon format. There are several different methods for doing this, and each has its own advantages and disadvantages. One option is to use the Windows Image File Format (WIF), which is supported by most modern browsers.
Another option is to use the Web Icon Favicon Format (WIFF), which is more versatile but may not be supported by all browsers. Ultimately, the best method for creating a favicon will depend on the specific needs of your blog.