After signing in, go to My Account > Preferences. There are 3 tabs on this page, which each affect your signature.
- Signature Options - Enter your contact information, upload a logo and add links to your social media pages.
- Signature Layout - Select whether your footer should be right aligned, centered or left aligned, and what contact info items you want to display by default.
- Favorite Styles - Set the background color and text options that will display on your card by default.
For detailed instructions: