Cloaking is when you have a separate page designed for search engines and something very different for your real users. Avoid cloaking, if you want to be in the good books of the search engines. Cloaking was a much hyped issue few years ago, but now the search engines are smart enough to recognize cloaking and other unethical forms of SEO. Try to avoid cloaking as much as possible.
Guaranteed SEO Experts
Avoid choosing those SEO firms which guarantee you a first rank in Google or other search pages. No firm can guarantee such rankings. Even top search pages has quoted that they don't tie up with any SEO company, hence there isn't any point relying on such fraudulences.
Automatic Site Submission
You don't need to submit your website to search engines every month. Submit your website once and wait for few weeks to get indexed in the search engines. Sometimes it takes months to get listed in search engine's pages. This depends on your SEO work and website credibility. Don't submit your website every week or month as this might hurt your website's image. Few people use software that automatically submits your website in weekly or monthly bases in search engines. This can penalize you, once you get caught by any search engine.
Haste Makes Waste
SEO requires lots of patience. It is an ongoing process. You cannot reach top ranking in any search engine in two days or two weeks time. There should be enough perseverance to attain a good rank in search pages. Don't be lured by SEO firms who guarantee thousand search engine submissions. Sometimes these firms only target your money. Don't waste your time on finding such guarantees. Be firm in your approach and have the courage to press on.
Flash Technology
Avoid flash in your website content. Flash makes your website heavy and difficult to download. Don't use such technologies which search engines don't understand. Develop your HTML coding as this is the system understood by all search engines. If you use the right coding and format then search engines will be able to read your site easily. This can further help you attain a better position in search pages.
