How to make a dress without a pattern?

[bwaybaby]

I was watching the film "Paris Texas" the other night and near the end, Nastassja Kinski wears this really adorable pink sweater-minidress that I'd really like to replicate.

 

This is what it looks like:

 

 

 

I'm thinking crochet, because knitting is just too complicated and tricky to shape. Crochet with a really hairy lightweight pink yarn..... but I've never made a dress without a pattern. Hell, I've never made a dress at all. This is going to be a very small dress (I'm a petite girl, only about 5"2 and 88 pounds) but it seems daunting. If I mold it to my own body I'm sure it will look great, but I'm not quite sure where to start. Can anyone give me pointers on what's the best way to approach this particular project? 

[Granny Square]

I would guess she was wearing a sweater (top) as a dress, dresses were long not short when the movie was made in 1984. Sweaters were typically oversize back  then, also shoulder pads were big (ha, I meant in style, but they were BIG, too).  If I were doing this I'd find a sweater pattern and adapt, rather than starting from scratch.

 

You might think of pairing a more normal yarn with an eyelash yarn, it might be easier to work with (holding 2 strands together).  Not necessarily heavy yarn, maybe something like sock or sport weight.

 

I took a look, and am not having luck finding a similar sweater pattern with such a plunging back in crochet. 

 

You are tiny and these may be a bit large, to adapt for fit you could check your gauge to the pattern's, and do the math to figure out what gauge you would need for you.  Example, if the pattern called for 144 stitches to fit  a finished 36" across the bust, the gauge would have to be 16  stitches to 4".  If your gauge with a smaller hook or yarn was 20 stitches to 4", your finished measurement would be 28.8".