Materials: to make a dress for one year old girls.
2 fabrics in contrasting colors.
Fabric No. 1 - make Sure that this fabric has ripples something like corduroy, denim. Will be better than quilting cotton.
Tissue No. 2 - you can use any lightweight cotton fabric.
Buttons - two buttons match the fabric.

Measurements:

Measure the child's shoulders to determine how wide should be the U shaped neckline of the dress. Let's call this distance NW. I have it out, Measure 10 cm from the point where neck and shoulder meet to make the depth of the cut. Let's call it ND. It is 7.5 cm in my case. You can also determine how deep you want the neck back. Let's call it BND. 

Construction:

The first drawing allows you to cut the collar to the dress:

1.

Fold the fabric 1 In two in width, now fold it again about 20 cm to Draw a line in the following way. You will get two rectangles, one inside the other.

 Note: If my pictures look not proportional, it's because I just took NW+3 and ND+3 for the outer rectangle. However, after finishing the dress I realized that a little wider clamp would be much better. So that's why I pointed out 5 inches instead of 3.

2.

Now, using the rectangles as a guide, mark the cutout on the inner rectangle and the yoke on the outer rectangle.

3.

Cut along the curve line, and deploy.

4.

Repeat the same for the neck and back, just to replace ND on BND.

5.

Here is the front and back of the neck and lining.

6.

Now sew along the shoulders and neck line (inside the semicircle).

7.

Make notches along the curved line. Caution do not cut the seam.

8.

Get, good.

9.

Do the same with the piece for the back of the neck.

Now we can start to work with a skirt.

10.

Sew along the length to make up.

11.

Turn out and fold along the length, so that the seam falls on the fold. In the picture above, the seam toward the left side. Now cut a curve about 5 cm in radius at the other end. This is the neckline to armhole.

 Note: this will be only part of the openings, not the complete arm.

12.

Expand. Here's how it looks.

13.

Now turn the tube inside out again so the wrong side was outside. Now take the piece of fabric # 2 and place it under the armhole so that right sides were together. Now sew along the curve line. 

14.

Cut out the unnecessary parts from the fabric.

15.

Cut off the excess fabric along the curve so that you'll be left with 4-cm wide strip parallel to the curved line.

16.

Remove the excess fabric inside.

17.

Fold the strips inwards and sew. I decided to sew it inside manual suture. Just because I feel better when hands are sewing. You can either manually sew binding to armhole, or just use a sewing machine. Repeat for the other armhole.

18.

Now sew two parallel lines along the edge of the fabric, from edge of armhole to the other. Pull the bobbin threads to gather the fabric. Repeat with the other side of the fabric from one armhole to the other.

If there is a seam in the middle, is the back of the skirt, and if not, then it before. 

19.

Now baste collar to the skirt, stepping back 5 - 6.5 cm on both sides.

 Note: You can always use pins to hold all three layers together, but I have a phobia of the pins. I avoid them as I can, especially on children's clothing. This is my worst nightmare that I could leave the pin in the finished product, and it will stick in the baby... Oh! So you can use pins, but I'm much more comfortable with large stitches.

20.

Now sew along the temporary stitches as close to the edge. You I can't see my seambecause it is made here in green thread. Remove the temporary thread.
 

Now sew two buttons on the front of the shoulders. You can use any other fastening means. For example: hook, Velcro or buttons. I just love how the buttons look, that's why I made buttons. The hem of the dress, fold over once and sew, then fold again and sew. And you're done!
 

Honestly, I'm not completely happy with the proportions of the dress. Don't be afraid, experiment. And you'll do better than me!