The yoke is the pattern piece for the upper back. The back piece can be sewn on with pleats or gathers. The yoke often ends at the shoulder seam, but can also be directed slightly forward. Yokes can be straight, bias, or pointed. If you look at a garment from the inside, you'll notice that the yoke is doubled, meaning a yoke is sewn against it from the inside. This way, the seams are neatly concealed and clean.
First, pin the yoke pieces to the back piece. The back piece is enclosed by the yokes. Place the yoke, which will be on the outside, right sides together. Place the inner yoke, right side facing, on the left side of the back piece. The notch in the center back allows you to neatly place all the pattern pieces on top of each other. Starting at the center back, pin left and right until the seam ends.
These three layers are now sewn together with a 1cm seam allowance, so that the first seam is hidden. 
Fold both yokes upward and iron the seam neatly. A little tip: We stitched the yokes at a distance of the stitching foot from the seam. 
Now it's time to join the yoke to the front piece in the shoulder area. This method is also called the "burrito method . " 
First, sew the top yoke to the respective front piece, right sides together.
Once you have done this with both shoulders, next roll the back piece up to the yoke seam. 
In the picture, you can see that the inner yoke is facing down. Do the same with the front pieces, then fold the top shoulder edge onto the bottom shoulder edge. 
Sew these three layers together. Then you can simply pull out the contents, and your yoke is beautifully finished. We like to use the stitching between the armhole seams, as the neckline tends to stretch and can become distorted.
Your yoke may be too narrow at this point. In this case, you'll need to turn the package through the neckline. It's best to sew a support seam at the very beginning of the yoke pieces at the neckline. To do this, simply sew along the edge with a large stitch, the width of your foot; securing the seam isn't necessary. This protects the fabric from distorting when turning, which can happen very quickly in places where the grain is partially at an angle. The seam allowances face upwards, into the yoke, and lie neatly between the inner and outer yokes.
Iron the whole thing flat, making sure you don't iron the ruffles flat.
To continue working, we basted the layers together at the neckline and armholes with a large stitch. This prevents any shifting.
You should also neaten the yokes at the armholes if you want to add another sleeve.
Have lots of fun with it!
