tips for sewing a divider in a backpack

[BDub77]

Hello All,

My next project will be a backpack and right now I envision making it a turned bag. Unfortunately, that will make it very difficult to add a divider so that there will be two (or three, possibly) compartments.If you sew the divider in first, the bag can't turn. Sewing it in after turning is a bit of a nightmare, in my limited experience. You can't see what you are doing, and your hands are always in your own way. All I can think of at the moment is to sew in a flap before turning - maybe something 1" wide that runs around the perimeter where you want the divider to go, and then after turning sew the divider to the flap you put in. I guess it might be slightly easier, but still painful/slow/irritating. So, I'm wondering if anyone here has a tip or trick for more easily sewing a divider into a turned bag? Many thanks for any help given.