First of all you need to avoid from using black hat seo techniques and you should try to build traffic based on the quality of your content.
Sometimes you do not know that you are using black hat seo techniques for promoting your website there I have mentioned below some black hat seo techniques.
Keyword Stuffing: This technique is most commonly used and in this technique a large number of common keywords are used on same page. Where there is keyword stuffing there is not quality in contents and it is done jus to attract search engines.
Hidden Texts: Same like keywords stuffing and these keywords are most probably used at the bottom of the content in small fonts or with same page color to hide it. Search engine most probably will ban your site if you will use this tactic.
Cloaking: This technique is mostly used by webmasters in which information provided to search engine is different from the information provided to researchers.
Doorway Pages: these are specific pages on a website whose objective is to get traffic on specific keyword or phrase and these have not useful content inside them. These pages can result is removing of your site automatically as soon as someone report it.
Redirecting: This technique is mostly used by webmasters in which visitor is redirected legitimate content.
You will get top ranked using black hat seo techniques but you will get banned from search engines as soon as search engine will caught you and search engines like google are pretty smart to do so.