As far as people who make dresses go, I'm probably weird. I can't sketch, I don't drape, instead I look at existing patterns and figure out how to graft them together. Sometimes while I'm working I'll completely change my mind. It's like doing a weird flat puzzle that becomes this cool 3-d thing.
I like to work with Kwik Sew brand patterns, and usually start from one of their swimsuits, ice skating dresses, or leotards. Today I'm using view B of Kiwk Sew 3272, and grafting it on to either an 8-panel skirt (that's a skirt made of eight pieces that flare out) or a layered skirt (to get my take on the ruffly "cupcake" look that is in fashion right now). If I do the layered skirt, it will be loosely based on Burda 7879.
So anyway, I've picked my base pattern, taken my measurements, and used tracing paper to trace my size off the printed pattern. I do this to save the printed pattern in case I want to go back and make a different size or variant later. Then I cut out the traced pieces and play with them to see how things fit together so I can create my Frankenpattern. Sometimes I cut up and re-shape the pattern pieces, for instance taking something that was meant to be one piece and splitting it into two. One of the things I'm going to do for sure this time is combine the panties and top part of the Kiwk Sew patterns together into one piece -- I don't need a waist seam on that leotard because the skirt is going to be attached to the outermost layer of the dress.
At this stage it's important to make sure you have enough fabric for what it is you think you might want to do. I'm going to go measure things and think for a while.