Materials:
* At least 1/2 yard of each of the fabrics (more if you plan on making a diaper cover with ruffles)
* About 12" of the fabric for the ruffles on the skirt
* 1/2" double fold bias tape
* 3 buttons
Ok, to begin with you need to make a pattern. Hands down, the best website to go to for instruction on this is Shwin & Shwin. Essentially, you will draft a pattern from an existing dress or top that fits well. For the smocking, I added 3" to the middle of the front. For the button flap, I added 2 1/2" to the back. I did a lining for the bodice, but not the skirt. For the sleeves, I did a longer version of the sleeve that the Shwins used on the Yellow Dress. For the skirt, I used the width of the bodice and added 4" to each side for the front and the back, then I drew the petal front. Below are pictures of the cut fabric, first the lining, then the bodice, then the skirt (I really should have ironed better...):
With right sides together, sew the sleeve to the lining along the bottom of the sleeve, then make snips at the curves and top stitch as you did around the neckline. Fold over and iron. Once right side out, make a basting stitch around the shoulder of each sleeve and ruffle to make it a puff.
I found in multiple places a nifty little trick that takes the headache out of attaching sleeves to the bodice. The best pictoral representation is by Especially Creative Broad. Most patterns have you attach the front and back bodice at the sides then "fit" the sleeve into the opening and you are left with the incredibly annoying task of trying to sew that with your sewing machine, thus the headache. So, how you will do it is you will pin the sleeve in place leaving the bottom of the sleeve and the sides of the bodice unpinned. Sew in the sleeve around the shoulder. Zigzag stitch the excess fabric to reinforce the seam and prevent fraying.
Next, I ripped 3 strips of my gray fabric at 3" wide, then I cut 3 lengths for the front and two backs of the bodice. I folded these strips in half and ironed them, then pinned them to the bottom of the appropriated bodice piece. Then, pinned and sewed the bottoms of the sleeve and the sides together.
Now to the skirt. I attached a bias tape along the bottom in an effort to use less fabric. To do this, unfold one side of the bias tape and line it up the edge with the edge on the wrong side of your skirt piece, then pin. Sew this to the skirt along the fold. Then fold the bias tape over to the right side of the skirt piece and line it up with the seam just made (red dotted line in the picture) and you can either do a straight stitch, zigzag or decorative stitch to attach this side of the bias tape to the skirt. Do this for all of the skirt pieces, including the petal overlay.
I attached the remaining strips of gray fabric together (I would suggest doing a 45 degree seam here, I didn't and regret it), then I did a quick rolled hem, which I learned from Grainline. Fold this long strip into thirds lengthwise (it doesn't have to be exact since you will ruffle them anyway) and cut along folds. Place a pin in the top center of each strip, then do a basting stitch along the top and pull one of the threads to create a ruffle from each strip. Line up the center pin of one of the strips with the top center of the front skirt piece and pin the ruffle along the top then sew together.
Next line up the center pin with of one of the remaining ruffled strips with the top middle of the bias tape and pin along the top of the ruffle, periodically lining up the bottom of the ruffle with the top of the bias tape. Again, because this is a ruffle, it doesn't have to be perfect. Then sew along the top of the ruffle.
At this point, you should have two ruffles sewn to the front skirt piece, one at the top and one almost at the bottom. Now, to attach the remaining strip, center it vertically and horizontally as best you can then pin and sew along the top.
Position the petals on top of the ruffled front piece, then with right sides together, place the back piece on top of that and sew the sides. Place a pin in the top center of the front and back skirt pieces. Ruffle the top of the skirt for the front and the back separately and using the same method as the gray strips.
The next step is to create the flap for the button. Fold and iron 1" of the flap side of one of the back pieces, then fold over 1" again and iron. Place a pin in the top and bottom to hold in place. Repeat for the remaining back piece. Mark and sew button holes. Overlap the flaps and pin.
Place and hand sew buttons.
You could be done here, but I took it a step further and made a ruffle butt diaper cover. I followed a tutorial by Made for the diaper cover, then looked to Daydream Believers for the ruffle part.