This is pattern piece for the main body of the coat. (From the previous link.)
Measurements are as follows, in inches:
B-33.5 (on fold)
This is the pattern piece for the closure part of the coat.
Again, measurements are as follows, in inches:
A-27.5 (on fold)
D-12.5 (I cut this at 6" when making the coat for a male, otherwise it will be in the way, and he will pee on it.)
These measurements are for an adult size Dane. Ferg was about 32" tall and weighing 120 lbs when I made my practice coat out of scraps, and it fit him a bit huge.
You can see how it hangs off his butt here. For this one I forgot to cut down the width of the belly strap, so it's in the way too, and the neck is a bit too large, so it kept slipping back. You'll have to adjust according to your dog's size, but I believe the instructions for that are in the original forum post I linked above.
When making Ferg's official coat, I cut down the measurements (a bit too much- oops!) to make it more puppy friendly. I also cut off the portion that would totally cover his butt, and now I wish I hadn't, because the coat slips around and won't stay up as well. It will do for now, but when I make a big boy size, I'll stick to the original design with the boy modifications.
Anyway. Once you have your pattern drawn out, cut out the fabric. For the good coat (the black and blue version) I used black Kona cotton on the outside and lined it with red fleece. I stuck them together with basting spray, then sewed the stripes down the back to keep everything in place. I used cutesy decorative stitches, and it took forever for each row. Bad idea. I suggest if you are doing it the same way I did, stick the fabrics together before cutting them out. Next time I will probably be lazy and use quilted fabric. You could even scope out thrift stores for old quilts if you wanted. Cut out the 2 main pieces. Next you'll want to measure the neck portion. To do this, I held it straight with my hands just to get an estimate for the collar portion. The original instructions suggest 20" by 7". When all your pieces are cut, you're ready to assemble the coat. For the main body, sew the sides marked "A" together. You can attach your collar before or after this step. I am lazy, so I did it before, which was easiest for me.
IF you are using bias tape to finish the edges, I discovered on the black/blue version that it works much better to bind the edges of the belly piece before sewing it to the body of the coat. I bound everything but side "B" then joined together. Line up the center of side B with the seam on the front of the coat, right sides together, then sew. There are 2 small seams you'll sew on the back end of the coat, then you can finish with bias tape around all the edges. On my practice run I used all fleece and it went together much quicker- no need to finish fleece edges, so I just sewed everything together and left it as is. To fasten the belly piece, I sewed on velcro, but you could easily do snaps or buttons if you prefer. I thought velcro would be best for a still growing puppy. You're done! Sorry for the lack of pictures- I did not originally intend for this to be a blog post, so I just put the coat together in a hurry and without my camera! Feel free to contact me with any questions, and if needed I can try to add in some more pics.