I do see a lot of mistakes when it comes to SEO, here are some of the top 10 I think are among the most important. Remember there is 100′s of things and they all need to be done together, however if I was going to just do 10, these would be those 10.

1. Title Tags
2. Description Tags
3. Keyword Tags
4. H-Tags
5. Duplicate Tags
6. Content
7. Out bound Links
8. Query Strings
9. Picture Dimensions
10. Alternate Picture Tags

Title Tags- This is what tells your reader what the page is about.

Description Tags- This is what comes up on the Google search results telling the searcher what your page is about.

Keyword Tags- This is what tells Google you have the most interest in for the keywords on your page.

H-Tags- H1-H2 and so on represents the paragraph broken down for each keyword.

Duplicate Tags- This is a no no. Do not be lazy and make sure you do a separate tag for each page

Content- Write content naturally and flowing. Hire a copywriter if you cannot write.

Out Bound Links- No more than 100 out bound links per page. I don’t make this up, straight from Google.

Query Strings- To many query strings on a certain page can cost you valuable points. Keep it simple stupid is a very old quote.

Picture Dimensions- Brownie points with Google, this tells them how large a picture is so they can plan for it.

Alternate Picture Tags- With out these Google has no clue what the picture is. Name it what it is silly, it will only help you.Title Tags- This is what tells your reader what the page is about.