MONDO(2 1/2" squares): You will need 192 small 2 1/2"squares for the bag and extra if you are using them for your handles
MONDO (5" squares): You will need 48 large 5" squares
MIDI: You will need 108 small 2 1/2" squares
Lay your interfacing fusible side up on ironing surface. Place fabric squares right sides up between dotted lines on interfacing. Fuse with Steam. You could use a silicone pressing sheet or a piece of parchment paper would work too, so that your iron doesn't get all sticky. IF using 5" squares, cover 4 squares at once.
Don't worry if you need to change a square after its been pressed on. Just repress it and pull it off which warm, and replace it with a different one that you like better. Oh yes, i would suggest maybe placing some darker ones on the bottom part so they don't show the dirt and wear as much as a lighter square.
If you would like to prepare your straps ahead of time, you could. BUT, i know we are all busy and we should have time for them in class. (The straps can be plain or with squares left over from those cut for the bag.)
We shall cut lining and fleece in class as the trips will be a little different size than the panels for the outside. You could also have a couple of different fabrics for the inside as all four pieces do not have to be the same. Sometimes you could have one panel that has a large pocket different so that you could see and find it very quickly.
If you have any questions, please feel free to email.