You almost describe me perfectly. I'm 5'4" and busty. I also have broad shoulders and a small waist.
Here's what works for me:
1. Structured clothing. This work for me most of the time since the structure in the clothing can hide many flaws becasue the clothing creates the shape; not your body. When I say structures I mean items like blazers cut where the waist nips in like to Cs really helps make an hourglass shape.
2. Tops that show some skin like V necks and scoop necks. I'm not talking about revealing clothing; just tops that show the neck and collarbone. It helps break up the chest and makes it appear smaller. I avoid crew and turtlenecks or else you get a monoboob - even with a good bra. I tend to find knits easier to fit that other tops like button downs because they will stretch to accomondate a chest and still cling at the waist. I love empire waist tops because I have a small waist and they call attention to the thin area below the bust. The tick is they have to be close to the body, they can't be too tight.
3. Get a good bra. Keeping the girls where they should be helps make you look thinner, better posture, etc.
4. Wear fitted (not too tight) pieces on top and looser ones on the bottom to draw the eye down and balance the body. It doesn't have to me looks but pick straightleg or boot cut over skinny jeans. Or choose a trumpet or A line skirt (or a pencil skirt with ruffle details) over a tight pencil skirt.
5. Skirts should hit the bottom of your knee. I know this sounds wierd since we're petite but it help balane you out and keeps you from looking top heavy.
6. Avoid bulky fabric on top like chunky sweaters.
7. If you have broad shoulder too avoid styles that add volume to the shoulder area like puff sleaves, halter tops, shoulder epaulettes (on trenches), etc.
8. Heels are great but avoid anything higher than 3 1/2 inches. I find 2-3 inches gives me some height while looking proportional to my build.
9. Try to wear lighter/brighter colors or patterns on botton and dark, plain tops. This also helps draw the eye down.
Here are links to some books that helped me a lot in case you want to learn more. I found these books had a good grasp on how to dress a larger chest (many make suggestions but don't have a clue):
http://www.amazon.com/Dress-Your-Be...4196042?ie=UTF8&s=books&qid=1182468503&sr=8-1
http://www.amazon.com/Pocket-Stylis...2050026-4196042?ie=UTF8&qid=1182468503&sr=8-1
http://www.amazon.com/What-Not-Wear...2050026-4196042?ie=UTF8&qid=1182468503&sr=8-1
This one isn't very good at how to dress body types but it's great for ideas on how to put pieces together:
http://www.amazon.com/Lucky-Shoppin...2050026-4196042?ie=UTF8&qid=1182468503&sr=8-1
Feel free to request more infor or PM me for any more info.