This is quite a long post so you might like to get a coffee or cup of tea before you start reading.
I decided to embroider some decoration onto singlets for my Godson's new baby, due in January 2014, and back in early December '13 I was looking at the Semamori Patterns I had found at Sri threads .

Since that time I have been doing a bit of experimenting with those original patterns. There were three major constraints to take into consideration.
The fabric. The kiminos that these designs were originally embroidered on were woven fabric, I am using knitted fabric and a rib knit at that. Added to this was the variability of the rib between different brands of singlets. This meant that I couldn't use the original stitches. They wouldn't accommodate the stretch of the fabric and the babe could catch their fingers in the stitching. The other problem with the fabric was how to transfer the design onto it? I had about three or four experiments before I found a solution.
The thread. This was originally a cotton thread but again this just didn't work with that stretch fabric.
The size of the designs. When I charted them out I found that they were quite large. This is fine on the back of a garment but there wasn't the same amount of fabric available on the chest of the singlet. Now, this was my own assessment about the size of the design. When I did a survey amongst family and friends, the men all liked the large designs, the women the smaller ones. So I think size is very much about personal choice.
I decided to select my singlets from Target and Coles stores because these were the most readily available.
Thread - I experimented with both cotton and silk threads and found that 1 strand of the Madeira silk thread gave the best results on both brands of singlets. I did try a z twist silk but found this one behaved better on the rib fabric and washed well. (Mary Corbett reviewed the thread here.)

Fabric - Both were labeled 100% cotton but there was a difference in the feel and stretch of the fabric.
Target home brand had a smaller rib and held it's shape better. (Made in Cambodia.) This made it easier to stitch on.

Coles singlets were made by Bonds were very soft to the touch but the rib was floppy. (Made in China.) This required more care with the stitching.

(Both singlets were labeled the same size but the Bonds singlets were quite a bit smaller.)
Embroidery Stitches -
The best was stem stitch and for shorter distances straight stitch. Other line stitches didn't express the essence of the patterns and back stitch was straight out horrible.
Transferring the Design -
The best results were achieved using a water soluble pen and a firm surface under the pattern. ( Don't use transfer carbon it just stains your fabric so badly you will have to bin the singlet.)

- I made pin holes in the pattern at line points.

- Marked these points onto the fabric with the pen.
- Removed that pattern and joined up the dots.
- On the small patterns I didn't put in all the dots only the main ones. The smaller details were added after I had stitched the main parts of the pattern.
- After stitching I washed the marking pen out under COLD water.
The size of the Design -
So here are the five samples that I stitched and I think the size comes down to personal choice.
Target home brand singlets, two large motives one small, (middle).

Coles Bonds singlets, two small motives. (The third singlet is in the bin.)

I have included fourteen different patterns with both sizes for each design as a PDF download.
PDF - Download Good luck motives 2
Conclusion -
These designs make charming motives on babies singlets, are original, not gender specific and have meaning. I will be using them again.