I am not using any black hat techniques as if affects the results permanantly

Black hat is not good now since searches get familiar. Here are what you are in need,
Hidden Text or Links
Keyword Stuffing
Reporting a Competitor
Sneaky Redirects
Cloaking

Google wont follow Black hat SEO.

Black Hat SEO does not follow the guide Line of search engine.

Cloaking
Doorway Pages
Keyword Stuffing
Hidden Text
Link Schemes
Article spinning

Some popular black head technique is
Keyword stuffing
Duplicate content
Doorway pages
cloaking
Hidden Keywords
Paid links