It took me a little while to blog about this, in part because I've been trying to remember how I did it. This was another project form that Lazy President's Day Afternoon I had and because of that I forgot to take photos after I was halfway through and nothing was done with any sort of template. Welcome to my random way of crafting!
Step 1: You will need two fabrics: (1) for the outside (I suggest a heavy weight home decor type material) and (1) for the inside (mine is a lightweight cotton print). How much you will need of each depends on how big your bag is, how many pockets you have, etc.
Step 2: Figure out how big you want your shoulder bag to be. Mine needed to carry a laptop case, at least two notebooks (one for work, one that I carry for an ideas I have), a binder (again for work), and a variety of pens, markers, keys, wallets, phone, blackberry, internet stick, etc. I like to have a lot of stuff with me when I travel for whatever comes up so in a nutshell it had to be BIG! Yours may not need to be so big. Try measuring some of your favorite bags for their size.
Step 3: Place the two layers on top of each other wrong sides (non-printed sides) together. Cut from this a rectangle that will be the base of the bag. I believe mine was 13" long and 6" wide (again, I need to keep better notes!). Fold the pieces (still wrong-sides together) in half and then in half again. Cut the corners so that they are rounded (how round you want your bag to be is up to you). You can sort-of-kind-of see in the first picture how I rounded mine (the smaller pieces)
Step 4: Using a flexible tape measure (dressmakers measure) measure the circumference of your bag. Cut that number in half and add 2 inches to it. Again put your the wrong sides of your fabrics together and fold in half (you know have a stack of four layers of fabric- 2 of the outside and 2 of the inside). You want the width of the fabric to be at least that number you came up with and the length to be how high you want your bag to be + 1". So using my example above, let's say that my circumference was 38" and I want my bag to be 12" high. I want to make sure that that the piece of fabric is 21" (38" divided by 2 plus 2") and the height is 13". These extra 2" and 1" are for the seam allowance.
Step 5: Cut out your rectangle (21" x 13") from the four layers of fabric. These are the sides of your bag.
Step 6: Take the rectangles of the outside layer of fabric and pin wrong sides together. Sew the 13" side together with a .5" seam allowance (Photo 2). Do this with the other side as well (you now have a column of fabric). Press the seam open with your iron (Photo 3).
Step 7. Stitch the pressed fabric 1/4" to each side of the side seams (Photo 4).
Step 8: Pin the bottom piece of the outside fabric to the sides (Photo 5 and 6). Stitch this together with the sides making sure to ease around the curves. Clip the fabric at the corner of the curves to just before the thread.
Step 9: Now I forgot to keep taking photos. if you want to put an outside pocket on now is the time to do so. I cut two matching rectangles of fabric from an outside and inside layer (about 5" x 8"). Sew the wrong sides together all the way around except for 2" at the end. Pull the fabric through the hole so the right side is out. Press the rectangle so it lies flat. Measure the center of a side wall and sew the pocket on. I like the paisley print showing out so I didn't fold the sides under.
Step 10: Do the same with the Inside fabric including the pocket (or multiple pockets) if you like. I put my inside pocket on the opposite side of the bag as the outside
Step 11: Now here's the part I wish I had a photo for because it took me forever to figure out. Turn both "bags" of the inside and outside fabric inside out (wrong side facing out). Pin the openings of the bags together so the right sides of the edge of the opening are together and the selvage (thready part of the fabric) are sticking out. Now sew around the outside edge leaving 2" open.
Step 12: Pull the fabric through the opening so that it's rightside out. Handstitch the opening shut and push the Inside fabric into the bag. You're almost there!
Step 13: Now it's time to make the straps. First you have to determine how long you want the straps to be off the bag. Again, I suggest you measure a bag you like from the top of the bag over to where it meets the bag again. Make sure that you take into account how large your pocket is because the straps will fall on either side of it.
Here's a little formula: (2 x length of the strap) + (4 x the finished height of your bag) + (2 x the width of the bottom of your bag) + 4". The 4" covers the seam allowance and also because my straps came up a little short.
Step 14: Cut 1 strap from each fabric the length that you've determined up there and 4" wide. Wrong sides together pin and stitch 1/2" from the edge all the way around leaving a 2" opening. Pull the strap right side out through opening and hand stitch that close.
Step 15: With the outside fabric facing, sew the ends together. Lay the strap flat (so it looks like a straight line, not a circle) and fold in half. Place a pin in each side of the strap at the fold. Now, fold the bottom of the bag in half lengthwide. Match the pins with the center fold on the bottom so that when pulled up the straps will fall on either side of the pocket and pin.
Step 16: Sew 1/4" from the edge of the strap all the way around, continuing past the bag and down again. I liked that this bound the outside and inside of the bags together, but if you don't like that you can sew the straps onto the outside of the bag before you attach the inside lining.
Step 17: Sew a button hole and a button and you're done!
Phew, that was long winded. I promise it's an easy sew once you figure out what you're doing. I'll try to post a better picture of the final product later!