In my opinion
- Forget for a moment how Preemo, Pete Rock, etc. sound. It's important to use them as references, but you've to build your own sound.
- However, i listened many amateur productions which are better than some professional ones. The most important thing is the taste in my opinion
- Study all you can about audio production as KonKossKang said and the mixing foundamentals. It's important to master the low frequency.
- Diggin for good quality sample.
- Listen a lot of unconventional music.
- Don't give up.