After reading and re-reading all the advice, I mushed up a lot of it and came up with a solution which works well for me. It's actually quite simple but effective, I think it's what stitchnluver was describing. I would never have thought it up myself though!!
So I quilted the top, batting and a piece of muslin. Here it is.
[ATTACH=CONFIG]518584[/ATTACH]
Then I made a lining the same size and put pockets on it.
[ATTACH=CONFIG]518585[/ATTACH]
All I have to do now is to sew the side edges of the bag together, inside out. That means the front, batting, backing and lining. Like this.
[ATTACH=CONFIG]518586[/ATTACH]
Then I can proceed to add the finishing touches like the gussets, turn the top down or add a binding and add handles.
So thanks all for contributing. This method is just a teeny tiny bit more work than my previous method and I think it looks way better.
I edited to add that when I originally thought of adding a separate lining, I was making it way more complicated in my head. In the past when I made a lining, it was essentially a 2nd bag complete with the gusssets and I fitted it inside the finished outer bag. This method of adding the lining during the bag construction is so much easier.
Last edited by KenmoreGal2; 05-01-2015 at 01:20 PM.