So first I had to find some tea towels that would have pictures and colors that a 3-year-old would approve of. I found mine at Target. Next I had to purchase matching binding and thread. I determined through experimentation that extra wide double fold bias tape worked best for me with my skill level.
Next, I folded the towel in half lengthwise, and then in half again, and marked the center. Then I used a ruler, and marked a line at an angle to the long side.
I then cut along the line with it folded. Next I opened it up and started attaching the bias tape with pins. All you do is fold it over the edge that you just cut and pin it.
I didn't measure, but I left somewhere between 12-15 inches for the belt tie on either side, and probably about the same for the neck loop. Since I was making this to be adjustable, I didn't worry about it being too much. After I stitched it around, it looked like this:
Now this is a bit too long for a child. So I folded the bottom of the apron and folded the belt ties up a bit and secured them with two safety pins. This now gives the child a big pocket and a more suitably sized apron. As the child grows, the pocket can be made smaller and the apron longer by adjusting the safety pins.
And here is the other one I did with strawberries. Note the neck loop is tied in this one to make it smaller.
I also googled how to color my own safety pins with nail polish to match. How cool is that?
Seriously, I was able to knock each of these out in less than 30 minutes. It is that easy.