Of course the normal way to create a favicon in WordPress would be to upload your file to the correct location via FTP. But for some looking for a simpler way (or one that may seem simpler anyway), another option is to install a favicon plugin and upload your icon file through that. There are a few favicon plugins around but we found that the All in One Favicon plugin was very simple to use and worked perfectly well.
Once you have added the plugin you can upload your file (favicon files are usually 32×32 or 16×16 pixels) using the settings page and voila, it will be there! You can also use a png or gif file for your icon using this plugin.
If you want a simple way to create a favicon then go to favicon.co.uk and they will create it quickly for you from an existing image that you may have. It’s a good idea to use a square image obviously. All very simple and done in a minute.