How to use a pregnancy pillow?

Hi all! My surgery is going to be on September 24th and I had a question about using pregnancy pillows. From what I gathered from posts here, it seems helpful to have to support lying on your back. However, I get confused on how to set it up to support being elevated the days immediately after surgery. Does anyone have any reference photos because I'm racking my brain over-time. (I'm still gonna get one because I need to sleep with something between my legs and arms. My body has forgotten how to not be sore in any sleeping position.)