I'm about halfway through the Burdastyle retro sheath dress wearable muslin, and so far I have learned a lot that will help me with the Daenerys version. As mentioned previously; I am making this muslin completely as directed to better see how to make my alterations and for a before/after pattern hack visual. I chose a quilting cotton as it is cheaper than fashion fabric. Generally you should try to use a fabric close in weight to the final fabric you intend to use, but for a dress using three different fabrics it is not an affordable option. Since quilting cotton is not stretchy it should not affect the fit.
Burdastyle patterns do not come with diagramed instructions or seam allowances. I used a seam allowance guide by Hollie which is a magnetic tool that sticks to the scissors allowing you to cut the fabric at the same distance (the seam allowance measurement which in this case is 5/8") around the edge of the pattern piece. This saved a lot of time where I would usually trace the pattern and add on the seam allowance in pencil then cut out! I am using french seams as I do not have a serger/overlocker, so I will not be pressing my seam allowances open.
Step one: After printing out and sticking together your pattern to cut out your fabric pieces, you start by sewing in the bust darts on the "upper fronts" aka bodice peices. Right sides together, pin/press the fabric so the dart lines are on top of one another and sew along the line. I find it helps to trace the dart markings onto the wrong side of the fabric so you can see where to stitch. When coming to the end of dart, do not backstitch but sew off the edge and then tie in a knot. You will need to leave long enough tails when you cut the threads to do this. This stops the fabric bunching when you backstitch on a tight corner. Do this step for both sides of the "upper fronts" and press the darts towards the centre.
Step two: Sew the both shoulders by pinning right sides together and stitching along the shoulder edge.
Step three: sew the shoulder seams for the two complete neck facings. You can tell which ends and sides should meet to form the shoulder seam by the pattern markings, refer to the original paper pattern pieces and match up the number fives. Sew right sides together. Turn out and press seam towards the back.
Step four: match up and pin the neck facings and the upper fronts right side together and stitch. Turn out and press down.
Step five: as with the bust darts, trace the "lower front" dart markings onto the wrong side of the fabric so you can see where to stitch and pin then sew along the lines for both darts. Press towards the centre.
Step six: line up the darts for the "upper fronts" and "lower front" and pin. The neck edges should meet at the centre front and the sides should be a continuous edge. Sewing a convex curve to a concave curve is tricky, you will need to use a lot of pins and maybe baste first to check everything lines up when you turn it out. Press seam downwards. I had to unpick this several times before I got the ease symmetrical so make sure you line up the darts and edges really well before you sew!