As a reminder, this is what you get when you google "germany winter" :
And this is the skirt -Burda Magazine 10/2011 #102- (in summer) :
The denim was quite pricey (16€/metre) and I had a "stingy moment", so I had to make do with just 0.80m (0.7y). (I couldn't fit everything, so the pockets are in a plain cotton).
So all this to talk a bit about what I do to make clean edge stitches -used a lot in jeans sewing-, while being lazy, stingy, and glamorous (always).
Most machines have an option to move the needle lateraly (yes, even the cheap ones). You can make the most of it in this situation. If you have a premium machine, you surely have the kind of foot shown at the bottom and don't need the tips.
Press your seam, move your needle to the far right (or left if you prefer), or to 1mm from the inside of your foot (if you can). Put your seam against the inside of your foot. Sew.
To make the additional seam, move your needle 5mm from the first seam (if your machine permit it). Repeat.
At school, I was taught to do the exact same thing on an industrial machine, with this type of foot (see below) -without moving the needle, as it's impossible-. Which is why RTW edge stitches are so narrow and precise. (to make the additional 5mm stitches, you just put the edge of your seam on/under the external side of the foot, half a foot being 5mm)
Or you can buy an edge stitching foot...