HubL code for social sharing in custom coded email
{% social_sharing "social_sharing" %}{% social_sharing "my_social_sharing" use_page_url=True %} These are the HubL tags. You can see the reference to them here: http://designers.hubspot.com/docs/hubl/hubl-supported-modules#social-sharing
For my needs, I was not able to use this. I had to create individual links in order to exclude the ones I didn't want.