being a writer. I've always found "selling stuff" difficult, and it started a long time before I was a writer.
Think back to your school days--elementary, junior high, or even high school. Remembering those days is a scary thought all by itself.
Do you remember all the various fundraisers you participated in? There was always something being sold--candy, cards, wrapping paper, t-shirts, fruit. The list was endless. But one thing all the fundraisers had in common was the prizes. If you sold so many items, you could earn a really cool prize, and the more you sold, the better the prize. And then there was the prize for the top seller.
I hated the fundraisers.
The lure of the prizes was great but I really hated asking people to buy the stuff. I hated the "pressure" that was put on me to sell a certain amount so that the fundraising goal would be achieved.

But what works when it comes to promoting books?

So, what works?
Honestly, I think everything and nothing. What worked a year ago may not work today, but a few months from now it could work again. I think the biggest thing is to keep writing...
And to keep posting about my books.