The Treasure in Deleted Scenes

Try to think about marketing and brand building while your writing and editing your story. Don't wait until you're finished the book to think of lines to share on social media. Don't just delete scenes that don't work. Save them in another document and share them on social media. I shared this one on Instagram and was pleasantly surprised at how many likes it got.

Lafeyette’s aura darkened. “Every time you two go at it, I want to kill you or myself. Aren’t we too old to act like this?”

Niah turned a half smile on Lafeyette. “Speaking of going at it—”

Lafeyette bowed his head with a groan. “At eighty-one, you two still act like darklings. Niah, you need to stop bringing up my active sex life before Vayle digs up your overactive past, without your consent.” 
Niah shrugged. Fear cracked through her aura. “Lord Lafeyette the Mouthy makes another appearance,” she mumbled.
“Preferable to Niah the Loose.”
I've mentioned this before, I think, readers like getting a behind-the-scenes look at the making of a book and the author's life. The deleted scenes you share don't have to just be the good ones, they could be ones that were totally terrible. I do something similar for the Behind the Cover posts. I share the failed covers.

You could also share images of your handwritten notes.

On a slightly unrelated note, I recently found a few hashtags that increased the number of favorites and retweets I got. It's not guaranteed. Nothing is guaranteed. Most of these are more for independent authors.