Cardi-3d - a design discussion

First, the test results from a sample I knit using the PERL calculator.

Attributes used:
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#Gauge:
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Stitches per inch: 5

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#Dimensions in inches:
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Circumference of sleeve: 6
Width of jacket: 5.75
Length of jacket: 9
Depth of neck: 1.5
Width of neck: 2.5
Width of placket: 0.8

Test result: Success.

Realistically, I was off on the intended gauge by about 3/4th of a stitch and so the cardi was slightly larger when finished.

Pictures of the knit sample:

Flying carpet? Or a stripey tail-less ray swimming away?

Note the 3 buttonholes.

See the reversing symmetry in the colour striping?

Some issues that I had to ponder over:
1. Technique for double decrease:
This was relatively simple. The one I selected was:
slip 2 knitwise, knit 1, pass slipped stitches over the knit stitch. This one works well as it gives a neat symmetry to the double decrease with the middle knit stitch sitting uppermost and prominent.

2. Technique for double increase:
Here I had a few options that I tested.
a. M1 left and right by knitting into the stitch 2 rows below the new row being worked.
This method creates large holes.
b. yo appropriately and knit into them twisted on the reverse row.
This too has much too much yarn for the stretchy garter to handle.
c. kf/b twice consecutively.
Not tried. If this one doesn't create a row of holes, it will be perfect as the look will match that of the double decrease of choice.
d. pick bridge yarn between 2 stitches, twist and knit into it, knit the next stitch and increase again like the first.
This was my choice as it gives strength and stability by knitting away the excess yarn. No holes to worry over whatsoever. However, the look does not match that of the double decrease.

3. Shaping on the RS or WS
If the increases and decreases all occur on the RS (or the public side) of garment, the stitch pattern thus caused will be available for all to see. If implementing this way, you'll have to select your double increase and decrease patterns to match up nicely in appearance. However, as the ones I had used were not so, I chose to do the increases and decreases on the WS of the cardi. The look is subtle and the stitch pattern in the corners (where the inc/dec occur) do not really become the focus. I liked it this way.

4. Striping
Any guesses on the striping design?

5. Discoveries
Garter is much slower than stockinette-based stitch patterns, and uses much more yarn to knit up the same surface area of fabric.

The cardi-3d is a basic pattern that can be used as template for incorporating stitch patterns and colours to make it more interesting. It's also a warm wrap for infants, the front-open making it easy to put on and slip out. Perhaps a knit belt can turn it into an infant bath-robe of sorts. I also have some ideas on changing the shape of the button panel using short rows.