Light, temperature, humidity and correctly used nutrients gives you what you want.
Apparently my buds are pretty fat and I use shooting powder I personally think it rocks. BUT you use it wrong, your plant's are not healthy enough or you just use it at the wrong stage and its game over. A lot of other so called flowering enhancers are easier to use.
What are you using at the moment nutrients and soil (or hydro method)?
Are your temps and humidity stable ?
Do you have good air flow ?
For Dense buds you need light and healthy plants thats it, there is no magic bullet or anything. Just healthy plants with good light and they will produce for you.
Give me the low down on what your using currently and maybe I can make a suggestion or two.
If you haven't used a hardcore booster before I wouldn't start with shooting powder.
Just the stoned ramble of a guy who likes to grow good pot, take it or leave it.