Something that may be very useful while adding the meta information or listing your posts in jekyll is to have available the first image that appears on its contents.

You can add some meta elements that will make your posts look more beautiful when sharing them on facebook or to create a twitter card:

Example of twitter card

jekyll-auto-image-plugin allows you to find this first image easily. You have all the information on its github page.

The plugin can be easily installed as a gem, and you can assign a default image for the site on the _config.yml file. Unfortunately, if you are hosting you jekyll web on github pages this plugin won’t work. A workaround is to upload the output of jekyll, i.e. the _site folder, instead of the jekyll source code.