What you need:
1 meter of fabric (I choose yellow)
thread (same colour as your fabric)
black lace (to decorate)
1: Make two semi circles in the fabric, one slightly shorter than the other.
2: Use a mannequin if you have one.
3: Place the fabric on the mannequin and arrange how you want the dress to look pin it all together inside out.
4: When you are happy with it sew it all together.
Now that is the easy way, trust me when I say there's nothing easy about this for mine I added black lace to the front it was a bit short for me (I have to protect my nether regions id cause a scandal) and also I placed bias tape around the edges to give it more structure.