Two DIY ideas

I like these two items but I think they are too expensive and could be easy to make myself at home:

$295 Kate Spade long knot necklace
I like how this could be very formal and fancy with an evening gown or just your regular necklace over a tee shirt.
To make this myself, I'd get a long (3 yards or about 6 times the length of the eventual necklace) piece of chain from a craft store and two large jump rings and a matching clasp. Then I'd take the chain and snake it back and forth like I was making zigzags. It would look like this: /\/\/\/\/\/\

Then I'd gather the chains at either end of the Zs and put the jump rings through the last link of the ends and a link in the middle of each Z point. Attach the clasp and you should have a long multi-strand chain necklace.

Fine, but then let's make it more interesting by tying overhand knots a few inches apart. This will take up a lot of length which is why you made sure to buy more chain than you thought you wanted.
The knots will pull on the chains a little unevenly but that is part of the charm, and the different chain lengths will cause the necklace to swoop and splay out between knots.

$130 Bailey 44 top
I like the drape of this top and the emphasis on the waist. I think the key is to do it in silk like the designer did for that soft but fancy look.
This shirt has a silk front but rayon blend back and I think that is gross.
What I would do is look for a slightly too-big boxy silk shirt at Loehmanns or Filenes Basement and then I'd put it on and pinch some fabric from the inside to get the location and folds right. Then just pin (safety pin since this is going back over your head) and sew where you want the gather to be.