I am definitely a "do as I say, not as I do" artist on this topic But I have been running a successful local Facebook page and this is what I've learned. I'll be putting these tips to work on my business page and I'm curious to see the results.
 
Facebook marketers advise on the importance of the 80/20 rule. That is, 80% of your postings should be original content, leaving 20% of your postings for product selling. Your original content should be related to your product or area of interest (photography, watercolor painting, etc). You may want to provide followers with a look into your process. Or the progress of a piece of work. Or the origins/meaning behind a holiday, especially the off-beat holidays GCU is known for. Or you may want to promote the work of another GCU artist, "Sharing" their FB posting. But remember that your followers are card shoppers, not fellow artists (although some may be following you) so don't get too technical.
 
The 20% of product-selling posts should still be more than just a link to a card. Provide the story behind the artwork or ask a question ("What are you doing for the Fourth of July"). Some marketers have success with sharing a small amount of personal details, but don't be an "over-sharer"; the details of your recent illness can just remain a mystery
 
Please leave your Facebook business page address below. My business Facebook page is https://www.facebook.com/PattiannMalynnDesigns
 
Pattiann

here's mine.  Of course, it's mostly full of my other business stuff and not just cards.  
 
https://www.facebook.com/pages/Sunshines-Creative-Endeavors/136077759887523
 
Perhaps someone can advise me how to better use social media?  I've liked the business pages of others and yes, I like Sherry's idea of sharing promotion of others.  I just don't know how I can fit in the time to do it just yet.

Thank you, Pattiann  
 
Here's my FB Page: https://www.facebook.com/photographytkdesigns