Now to the process. This definitely is not a project for a beginning sewer as this tutorial is more of a guideline based on what I did. However, don't be too scared. If you mess up, you can always go get another shirt from Good Will for super cheap and try again.
A men's dress shirt (the larger the better), 2 if you want a fuller skirt
Sewing machine, thread, pins, etc.
Some tulle if you want the skirt to poof out
4" ribbon for the flower belt
Button for the middle of the flower
Needle and thread
Dress or shirt that fits the child
Large paper or smaller pieces taped together
Start by making a pattern for the bodice and sleeves using the shirt or dress that fits and large paper (If you need more direction on drafting patterns, head over to Shwin and Shwin for an in depth tutorial). Then use the bodice pattern to determine how you will cut the shirt, keeping the collar and buttons in tact. Below is how I cut up my shirt initially. I used the cuffs to make the puff sleeves. As a side note, I have seen some tutorials that keep the button strip down the front by cutting along the side. However, I wanted to make this easy so I cut right through the strip.