Okay. I've gotten enough questions about that smocked Ice Cream dress that it warrants a few details. So here ya go.
First, if you haven't already, check out the tutorials I did a while back on marking and pleating by hand and smocking. That's where you'll find how to mark and pleat the fabric and some basics on smocking stitches.
Now let's figure out how to adapt the dress front pattern piece from a gathered piece to a smocked piece. Generally speaking a piece of fabric that will be English smocked needs to be 3 times as wide as the planned finished piece. For example, if I wanted to make a smocked panel of some sort that would be 12" wide when complete I'd start with a piece of fabric 36" wide.
Here's an Ice Cream dress front piece that I have pleated and ready to smock:
This is the back of the dress front. Its already marked and pleated and the pleat threads are tied off. You can see that I didn't pleat the whole way across because this particular pattern piece has sleeve portions at the sides (the blue lines traced at each side). I don't want to smock there so I left it alone and also left a healthy inch plain beside the sleeve portion. That way I don't have to worry about the smocking and the sleeves messing with each other.
So, to figure out how much fabric to begin with I measured the pattern piece for the dress front, decided how much of it I wanted to smock, and multiplied that part by 3. Like this:
Once your fabric is cut mark the sleeve shaping but don't cut it out until the smocking is done. Just mark and pleat the center section as shown in the other tutorial and your dress front is ready to smock.
I need to decide on a smocking design for this one and get it finished. Once the smocking is done the pleat threads will need to be removed and the piece will need to be steam blocked to its final width. Then the rest of the dress can be constructed as usual.