Step 1: Underwear tricks
Get a proper bra fitting and then splash out on a Push Up or Plunge bra as they're designed to push your breasts up and out. Foam, air, and gel inserts are made to be inserted into your bra but if you do this, make sure the fit isn't too tight and it doesn't look like you've been shot in the back by a couple of cruise missiles. Silicone inserts are good here as they're worn directly on the outside of the breast and look more natural than other inserts.
Step 2: Over time
Strengthening and toning the muscles beneath your breasts helps make them look bigger by making them sit higher and more evenly on your chest. Start doing some daily pectoral exercises like press ups and pull ups and over time this will force your breasts up and out.
You can also try massaging the upper and outer area of your breasts in circular motions each day to help stimulate circulation and tone-up the fatty tissue. Sesame seeds are also very effective in enlarging the breasts so try and eat several handfuls a day. If this regime still hasn't got your breasts growing as fast as you'd like then you should move to defcon four....
Step 3: Sex yourself up a bit
Horizontal stripes with a high neckline are a good way of increasing your breasts appearance but you should also try experimenting with ruffles and frills to draw attention to your cleavage.
Wearing spaghetti strap tops and accessorizing with low hanging pendants that fall just above the top of the breast will draw more attention to the bust area. If you're wearing a low cut top, apply eyeshadow or blusher, a shade darker than your skin tone, between the breasts to suggest shadows and cleavage. A touch of shimmery glitter on top of each breast will highlight the rounded top and make your chest look fuller.