I'm in the SEO business. The more I look up websites to do an analysis on them, the more I find web designers don't seem to care, or don't know. Now I understand that link building is probably a good 80% of SEO, but for web designers to almost ignore the internal optimization aspects of web design is just sloppy. It is like writing bad CSS code. If you take pride in your work, you just wouldn't do it.

I've added a checklist for designers to focus on while creating a site:

1.The URL
does it have a 301 redirect in the case of duplicate sites? (ex. www.omarblasgen.com vs. omarblasgen.com) it could appear like spam if you don't have one.

2.robots.txt
this is a very important entry point to a website for a spider.

3.Sitemaps (both .xml and the user sitemap)
each should have its own page.

4.Proper 404 Page
don't get lazy! design a custom 404 page that matches the site's theme.

5.Code Bloat
don't have it. make sure the code is clean and to the point.

6.H Tag Optimization
make sure you use h tags. they should be keyword rich and descriptive.

7.Cononicalized Pages
each page should be in its own folder. hover over a link on the main page. down in the bottom left of your window, what do you see? is it a bunch of garble? is it keyword rich and descriptive? it should look like this (ex. http://omarblasgen.com/background). don't place the code at the end of background (ex. http://omarblasgen.com/background.html) also don't build up the folders here. (ex. http://omarblasgen.com/aboutme/background)

8.Content
we all know content is king! the main page should have about 500 words. it should be keyword rich without over saturating it with keywords. the other main pages should be 250+.

9.Image Alt Tags
there not just for the visually impaired. make them to the point and keyword rich descriptions.

10.Site Authority Sculpture and Internal Linking Structure
this means something different now. before you would focus on links throughout your site to weave the pages together. now it is how you structure the site itself. check this out to learn more:
http://www.nicolasprudhon.com/google-seo/google-nofollow-update. also make sure the links are descriptive. make sure they don't say something like "click here". instead have them say where they lead. (ex. if you are linking to a page that is for selling running shoes, don't say for great deals on running shoes "click here". do say something like check out the great deals on our "running shoes").

11.Title Tags and Meta Tags
do a "site:" search for the website's url on google. (ex. site:www.omarblasgen.com). they should all have unique, keyword rich content.

12.Inlinks
this is external, so i wouldn't worry about it, unless you want to.

13.Keyword Choices
do a search for their main competition. do keyword searches. the keywords should be specific to what they are doing.

I'd love to explain things more. If you want me to take a look at your website, let me know.