If you are running a website, then your site must have higher ranks for relevant keywords in search engines because these days, search engines are major source of traffic.  Here I am giving some activities that should not be done while doing SEO, as they can make spiders your enemy.

• Do not write in the font as your background, it is used to be a trick to put keywords in white so nobody except the spiders could read them. These pages ranked high in the past and after getting bitten by a venomous spider are penalized or banned.
• Do not list keywords in your content: the spider is expecting readable text so the search engine gets alarmed when he reads lists like keyword1, keyword2, keyword.
• Do not use 2 times a title tag: only 1 title for 1 page.
• Do not copy-paste entire pages: spiders hate duplicate content just like most people hate it when TV keeps on repeating the same show over and over again.
• Do not use keywords in your keyword tag that never show up in your content. If you say your keyword is SEO but your content is about apples and pears this will make spiders angry.
• Do not use frames: spiders just don’t like it, although there is no penalty there. It’s just that spiders have a preference for “no frames”. If your date likes coffee, you don’t bring her to a cocktail-bar do you?