This is the before. Notice that there is an attached back cushion. That always presents a challenge and the usual way to deal with it is to pretend it just isn't there. Once you have the slipcover on the piece, you can't tell what was underneath anyway.
The sofa is in a bedroom and the new slipcover softens the harder lines of the piece.
The back view. I guess you can say that my signature is a button back. It adds detail and is so much cuter than a zipper. If a slipcover needs an opening of some sort, I always do buttons, unless it would look stupid. Normally, though, that is not the case. I've had many clients suddenly want to float the sofa or loveseat so that the back actually shows.
Ruffled side pillows with covered buttons complete the new look.