How do I implement Twitter Cards on my WordPress Site?
1. Install WordPress SEO by Yoast or another Twitter Card plug-in.
My clients and I use WordPress SEO by Yoast. This plug-in not only creates Twitter Cards, but it also sets up Facebook Settings, generates XML Maps, and submits the maps to search engines.
For Twitter Cards, the post’s first or featured image will be used. The default summary displayed is a set number of characters from your post content. You can customize this by adding your own summary in the Meta Description (under the post editor). This is the same summary used for Google Search results, Facebook, etc.
2. Apply to have your Twitter Cards appear on Twitter
You still need to tweet about your new posts. Twitter Cards appear when the url to your post is tweeted.