I do a lot of bags and pouches using flip-and-sew patchwork and I've been asked to do a tutorial.
First cut out your bag pattern pieces on fusible interfacing. I happen to like Pellon 808 Craft Fuse, but as long as it's fusible, it will work. Today's bag is view B from Burda pattern 8560. It makes up into a over the body sling bag. Here's one that I did a while ago using the same flip and sew method as we're going to learn today.

For this particular bag, I decided to use a big piece of Mollie's painted fabric for one side. So I cut that piece out and placed it right side up onto the fusible side of the interfacing. This is usually the shiner side or the side with the little bumps. Iron CAREFULLY making sure not to get hot iron onto interfacing.


Then I took a long strip of black and lay it right side down onto the painted fabric. Sew along the edge with a generous seam allowance, keeping the line as straight as you can. Then flip it over. Finger press the seam and move onto the next piece. You can iron it if you like, but be careful not to get the fusible stuff onto your iron's sole plate. Icky mess!
Keeping going across the bag until you reach the far edge. We'll come back and do the handle part in a minute. I decided to put in a folded strip. To do that, I cut a strip about 1.5 times the height of the bag and just put random tucks in it as I was sewing.


If the piece of fabric you want to use is not long enough, just piece another bit onto it. Press that unit and sew it onto the interfacing like any other strip.

Now for the handle, use the same method, but to add some interest, sew the units at varying angles. Just clip off the extra seam allowance before you sew the next piece on. By the way, bias stretch and grain line don't matter one wit in this type of patchwork because the fusible interfacing provides all the stability you need. Just don't sew yourself into a 90 degree corner. Think ahead and make sure you can proceed with straight lines.




Here's the panel finished before trimming. Iron it nice and flat, on both sides to make sure the interfacing has fully bonded. Looks all messy, huh?



But no need to panic. Just turn it over and use the interfacing as a guide to trim off all the raggedy edges.

Here's both finished panels.



Now for a little yarn couching. Find some yarn you like and set your machine to some kind of zigzag stitch. This is a soy dyed purple wool. I used a stitch that looks like chain link fence. Put on a regular stitch foot and place the yarn on the bag. Just sew over the yarn in a random wiggly pattern.




Here's the two panels with the yarn couched on them. Make sure your yarn goes all the way to an edge so it gets caught in a seam. Now I just need to put a pocket in the lining and sew the bag together.