This biggest opportunity you have to get your message out is by adding Suggested Share Text to your Twitter posts. This text is sent along with the image and link to your content when shared on Twitter. You can add one or more share text suggestions that can be used only for Twitter (to allow for the shortened character count).
To add suggested share text to an existing post, navigate to the Sharing tab while creating a post or on the Edit Post page, and scroll down to the Suggested Share Text area.
You can customize this text, and it will be shown by default to Members when they choose to share this content. Under Suggested Share Text, you can click the Add Another link to add additional suggested comments; members will have the ability to toggle through these in the share dialog.
You can add multiple share texts and your Members will be given one at random, they can cycle though them to choose the one they like best, or they can customize them.