Cutting:
Seam allowances are included - 1cm wide or as per marking clips!
Cut the pattern pieces from your fabric . Place the pattern pieces with the lettering facing up. Always align the grain arrow on all pieces in the same direction and parallel to the selvedge of the fabric. Transfer all notches from the pattern by making a 3mm cut with scissors or chalk and mark the ends of the darts. Notch the seam allowance along the fold, as this is always the center line. 
To sew this dress you will need a sewing machine and an overlock sewing machine, or alternatively the zigzag stitch on your sewing machine to neaten the cut edges.
Be sure to use a jersey needle and a stretchy stitch. This means that if you're using a home sewing machine, you should use either a zigzag stitch or a three-part stretch stitch. Then, finish all seam allowances with a zigzag stitch or another similar stitch to prevent fraying. The colored lines in the images show you, in addition to the description, where a seam needs to be sewn or glued.
When sewing, pay attention to the seam allowance included in the pattern.
Have fun sewing!
Video on processing the front part
Start by sewing the two back pieces together. Neaten the seam allowances together and press them upwards.
Then neaten the side edges and the hem of the back piece. 
Set the back piece aside and take one of the ties and the right front piece. Sew the tie to the front piece (the pattern will tell you exactly where to sew it). We also have a video on how to sew the front piece of the Marie: 
Then fold the strip and a piece of the front piece in half and sew the two sides together. Sew the ends of the ribbon together as well. In the photo below, I've marked the lines on the pattern to show you what you need to sew together. Pay particular attention to ensuring that points A and A, which are labeled on the pattern, line up.
The right front piece can now be sewn to the left front piece. For easier sewing, don't pull out the ribbon. First, sew sections B and B together (see pattern). Sew the front pieces together from the shoulder to point A. 
Then close the line C. This runs from point A to the side seam.
Now you can pull out the ribbon, i.e., turn the tie inside out, and iron the edges. Then neaten the side seams, the hem, and the attached neckline (here: the blue lines).
Iron the second tie in half and turn it all the way around. One end should remain open for turning. 
Sew the ribbon onto the right side edge at the level of the dividing seam. 
Iron the three small strips in half. 
Sew the shortest of the three strips, right sides together, to the back neck hole. 
Then I folded the strip to the left and stitched it on close to the edge. Make sure the seam allowance doesn't show. If the seam allowance is a bit too wide, you can trim it accordingly. 
Next, we'll start with the front neckline. It's very important that you mark the two points (here marked by blue dots) with pins. 
Then you can place the back piece, right sides together, on the front piece and pin the shoulders together. In the photo, I've again marked the hole with two blue dots. The ends of the back neckline end at these dots. Then fold over the facing from the front piece. 
Close the shoulder seams as shown by the blue lines in the photo. End at the two previously marked points. 
In the end the neck hole looks like this on the shoulder. 
Next, sew the sides together. I first ironed the hem up and then sewed the sides together. Then, iron the seam allowance open and sew the hem in place.
Finally, the armholes need to be finished using the two strips. Sew each strip together to form a ring and iron it in half. 
Now sew these strips on using the same principle as for the neckline. First, sew them on and distribute the width evenly. 
Then topstitch the seam allowance close to the edge and finally fold the strip inwards and sew it firmly.
