If you can't decide where to place the background stitch, leave it open until you stitch the other element. You can go back and fill in the background later.
Why not do the other areas before stitching the background you ask? Well it gives me a good sense of completion to get the background done. But it is really your choice.
You can be helped in this area by consulting the picture too.
As I work on the background, I am looking forward to watching the Super Bowl. I know there are shops that are hosting Superbowl Parties. I wish I could join you, but will stitch here in my room with the TV on. My career was in television, so I love to check out the commercials that debut within the game. But I have another reason to be excited about the game. One of my nieces is married to a Steeler. He is a member of the practice squad, but has played in a few games. My brother, his father-in-law, tells me he will probably not "suit up", but will be there ready to go if called upon. It is the ultimate, "put me in coach". Yeah, put me in for a play in the Super Bowl!
So enjoy stitching today and, Go Steelers!