How to Quilt This??

 
I've been reading Bonnies blog entries about how she decides to quilt things... I have always done in the ditch straight lines till I got my Pfaff last year for my birthday which can do free motion. Now I have done a bunch of meanders, but you can ruin a quilt with an all-over pattern like that if it doesn't need it...

How do you decide which way to quilt something? I still have so much to learn!! How would you quilt this scrappy flannel quilt? I plan on piecing the back with flannel scraps from some lovely Stasbusters!!