What is the most common mistake about SEO that i should avoid?

• Not optimizing for the right keywords thereby attract everyone who is not your target audience or customers.
• Not creating unique title tags, the more different yours title tags are the more your brand is visible and more it is not over shadowed as well.
• According to Chantal Bechevaise, Plagiarism is illegal without the right permissions and this can cause your website to be de-indexed which is basically to be banned by Search Engines like Google.
• Not making a website mobile friendly that way it is not accessible for those always on the go thereby you lose out.

Hi,

Don't use Link farm, Keyword bunches in Pages,Don't submit to search engines...

Regards

Sunil 

please avoid your proudness

Wrong Canonical tags

Not considering Page load time

Blocking CSS and Javascripts from search engines

Away from the traditional known mistakes/issues, one of the most common mistakes is copying/following the big brands SEO strategy without enough customization/research & testing.

Spam backlinks, over use of keywords in the content, copied content, no sitemap, too many blog roll links, meta tags not updated, 

Not following Google guideline can lead to google penalties in SEO.

Hi,

It's very long list but i'm going to highlight these mistakes:

Short content.

Automated article.

Heavy size images.

Fake back links

unnecessary java codes 

Hide text in page code 

Thank you