Hi everyone! I'm attempting to make a mid-thigh length woolen coat/overcoat (EDIT: to be worn over just a shirt in mildly cold weather, no other layers in the middle, hence the snug fit) with a pattern drafted by following the videos. (It was something I had already started before I found this video series). Since this is a coat making series, I think it's only fair to avoid any overcoat specific questions and keep my questions limited to what is covered in the coat making series - Improving the back fitting, wrinkles at the back of the sleeves and the neck-shoulder seam line direction. I'm not very experienced so any suggestions will be humbly accepted and much appreciated! 
I'm working with some cheap polywool fabric for a test coat before I attempt it with wool. I've drafted the coat pattern and simply lengthened it down and straightened the Centre Front line up to the collar to make a simple funnel neck coat for now. Here's the coat pattern I drafted using the same measurements as the video but head unit 8.5 And the toile I've made just to check the initial fit (not canvassed): 1. My first issue is back fitting. My normal posture is more erect than the default pattern. There was enough room in the center front (for a snug fit), but the back is quite loose. I have taken in 5/8 inches uniformly at the centre back seam, making the seam allowance 1 inch.
- Do I need to take in more at the CB seem and/or should I reduce the balance?
- Should I try to take it in a bit on the sides at the waist level?
- I haven't sewn in the front darts yet. I think that will reduce the overall waist circumference and will help a bit. I'll post again once I've done that.
 2. The other issue is the wrinkles at the back of the sleeves. From watching the fitting video I think I need to rotate the sleeves to adjust the pitch to where my hands naturally rest. Right now I'm using the back and front pitches marked from the pattern. - How do I know if the armhole depth/height is not causing this?
- Is there any other reason for the wrinkles in the sleeves? 3. The last issue at this stage is the direction of the neck - shoulder seam. It appears to be going back rather than straight to the top of the shoulder. - Is this by design? - I have tried to straighten it on one of the shoulders by simply marking where it should be and re-sewing it. Can it cause any issues if I choose to do that? The loose back and wrinkled backs of sleeves The neck-shoulder seem going back and the marked lien where I would like it to be The straightened neck-shoulder seem (please ignore the misleading blue lines) Thanks in advance for any help and suggestions! Rahul