Problem: Fitted shirts sized to your waist squish your boobs. Or you lose curves when choosing a top that fits your bust.
Solution: The Half-Vest Thingy...now you can prove that you have a waist while still retaining the ability for your chest to do its respiration thing.

"Aww, I have no waist...(and look retarded in this picture)"

"YAY! Look, Curves! And my chest isn't being crushed!"

Back (Stolen from a simplicity vest pattern. I drafted the front and front-side pieces myself)

Laces up, using my favourite new technique, hand-sewn eyelets made with tailor's awl. I used stretchy cord which is awesome, because I never have to completely unlace it. Although getting it over the bustline can be somewhat difficult.

Side-View, demonstrating the reason why shirts that fit my bust rarely fit my waist. (I feel sorry for girls larger than me. It must be impossible to find anything fitted that you don't make yourself.)

The Vest By Itself.
I got to finish off (except for a few minute scraps) the brocade I bought on sale to make my duster, which I also had enough to make a skort out of...and this vest! SCORE!

I may have seen something like this in real life before, but not that I can recall. I was honestly inspired-as I often am-by sci-fi television. This time, it was the half-vest thingies that are adorned by the women in Earth 2, most notably the character of Bess Martin (see above). Mine is a little more pirate-y with lacing instead of buttons, red brocade and my white blouse.
*Semi-Helpful Tips and Tutorial**TIPS*
I have a 42" bust and 33" waist, so I understand the top-heavy issue. But it doesn't look that intense here, right?
Well, I'll tell you why...
First off, my tricks for demphasizing:
-I love my sports bra, not the kind that gives you a uniboob. It keeps everything nicely contained while still giving you some normal-looking shape.
-Layers! Long-sleeved undershirts with moderate to high necklines conceal all that stuff your sportsbra is keeping in. Black is recommended, and works even under a white blouse!
Finally, IMHO, a busty individual looks more top heavy in a t-shirt that has no form. They cling to the bust and just sort of hang from there, obscuring the rest of the curves and making her look like an inverted triangle. Showing the waist reveals/emphasizes the curve and presence of hips (even if they are smaller than the bust), which in turn creates a more hourglass shape rather than the top-heavy triangle.
So, even though your breasts seem to be more out there, so are the rest of your curves that give you more shape and make you appear less top-heavy.
What you need (for my cheater's method):-a vest or shirt pattern you like/want to base your half-vest upon. I used Simplicity 4079. (unless you're keen to draft a pattern from scratch)
-I used brown packaging paper in this instance, because the cat kept pouncing and ripping up the regular gift wrap. Plus if you use a pencil, it will just go right through the wrapping paper if it's on a soft surface, say like the living room rug where I do most of my crafting.
-Fabric: I'm not precisely sure of the yardage, because I used leftovers, but my vest pattern calls for about 2-2.5 yds including lining. I feel that much less is actually needed.
-Sewing paraphernalia
-For eyelets: embroidery floss and a tailor's awl.
-lacing or cord, etc. Unless you opt for buttons
Here's How I went about making my Half-Vest Thingy: (sorry didn't take in-progress pics)
1. Because I'm a cheater, I first dug the vest pattern out of my collection. Since I wanted the back of my half-vest to be vest-like, I took the relevant pieces out and put them aside. For hardcore drafters, you probably already know how to go about designing a vest back (two center pieces in this case, and two side-backs, as well as two strips that serve as ties).
2. Again, because I am too lazy to to do all the measuring and designing,and too anal to trust my own judgment (in particular the under arm seams are unpleasant), I took the vest's side-front and front pieces as a basis. I traced them onto my brown packaging paper, in order to establish the curve around the arm.
3. In order to lower the "neckline", I basically did an educated guess sort of thing. I measured from where the shoulder seam would sit to my underbust, along my side so as not be skewed by said bust.
4. Ultimately, you should have pieces that look something like this:

5. Cut Fabric:
-back: 2 of fabric, 2 of lining
-Sideback: 2 of fabric, 2 of lining
-Strips for ties: 2 of fabric (double desired width of finished ties plus extra for seams)
-front: 2 of fabric, 2 of lining
-side front: 2 of fabric, 2 of lining
-2 strips of fabric for eyelets: 2.5" wide by length of front piece
6. Assemble pieces for back (make sure you place ties between back and sideback pieces). Attach side fronts to fronts.
7.Attach front pieces to back at shoulder seams.
8. Assemble lining in same manner.
9. With Right sides together, completely sew garment to lining, only leaving sideseams open.
10. Turn through shoulders and out sides. Press.
11. With right sides together, sew side seams as much as feasibly possible. You will have to hand sew the few remaining inches closed after turning seams inside. Pressing with iron will make this easier. (Sorry I can't describe this better...I'll see if I can locate/make an illustration).
12.For eyelets, sew two strips and turn so that you have two tubes. Press flat. Hand sew ends closed. Mark out desired amount of eyelets (I used 5 on each side). Sew eyelets- This is where I first learned of the technique, and they probably describe it better than I could:
http://www.vertetsable.com/demos_eyeletholes.htm13. Lace however you prefer (there are a surprisingly large number of variations).
14. Try on and feel stylishly geeky.