Finally, here's the dress I made using a 1-meter Nani Iro fabric and I used Gertie's fabulous tutorial on peter pan collars.
Sadly, the dress has a lot of flaws.
I barely had enough fabric for the collar pieces and I cut the collars incorrectly, ending up with two left sides. Gertie's tutorial is perfect. I made the mistake, because I cut my fabric while crying through "An Affair to Remember".
Still, I had an imaginary Tim Gunn tell me to "Make it work!"
As a n00b, I have issues with sewing around curves and no amount of pressing made the collars as round and as even as I wanted them to be.
The good thing about the busy print of the fabric is that it hides the uneven collars.
I have worn it once. It's not great, but wearable and cute. Except after one wash, I noticed that the bias-bound neckline and amscyce weren't as bound as they’re supposed to be. I used a purchased pre-folded bias binding and I didn't sew it as well as I sew self-made bias-binding -- the stitches didn't catch some of the folded bits.
But I don't think I'll fix this dress at this point, because I have so many sewing projects in the pipeline, especially after that Vogue/McCall/Butterick 3.99/2.99 sale.