Okay so Twitter Cards can be a bit of a pain to set up when they don’t just work straight away. It’s a bit of a faff with image sizes & meta tags and I was back and forth on the Twitter card validator a fair few times before I was happy with how they looked.
Hopefully this guide below will save you some time when setting them up yourself.
Twitter cards are even more important now that Twitter are choosing to expand these cards automatically on mobile. This means adding an image to your Tweet is not as necessary as it used to be. This is because if you have Twitter cards set up on your blog an image and link preview (see TechCrunch tweet below) will automatically show up on mobile anyway.