That being said, there are tons of things webmasters can do to help their sites perform better in search, so this list is not by a long shot finished. It is, though, what we think are the top ten strategies for better search engine placement.
These principles are my business Bread and Butter. I use them ALWAYS!!!!
1. Title tags
Listed by others as one of the Big Three (tags, links, and text), we're putting title tags at the top. The words in the title tag appear in the link that pops up in the search result. This is where you tell the search engine (and the would-be visitor) as succinctly as possible what needs to be known: company or publication name; relevant, targeted keyword or keyword phrase taken from the text of the page. Each page should have a title tag as Google, Yahoo & MSN Search rank each page individually, not the site in its entirety.
The order of the Big Three is very debatable, but really they work as parts of the whole; not one of them can be left out if the machine is to work properly. In this case, you probably understand that content should be quality, however that is defined, but it should also be rich in the keywords you are targeting to drive search traffic. That doesn't mean just throwing them in there like you're cooking up a pot of SEO gumbo, though. Keyword use and keyword variation should be natural and not overstuffed. For the visual text part of the page, focus on working in the relevant words and phrases you want people to find you for.
3. Quality Links
Or more specifically, back-links, links to your site from outside sources. Links are your letters of recommendation. If nobody's recommending you, or the recommendations seem phony, then it won't work. Authority links are weighted most heavily, of course, so try to get industry-related authority sites to link to your site.
4. Quantity Links
Authority (high quality) links are by nature more difficult to get, so you'll have to start somewhere else unless you already have the brand recognition you need from square one. Many SEOers propose "link-swaps" to each other and it used to be common trade to buy and sell links. But as Google demonstrated last Fall, you can't buy search engine love that way. In fact, you'll get the opposite of love. So, try to get as many links as you can from industry peers the good old-fashioned way – by promoting. Submit links to respected directories like DMOZ and Yahoo, as well. A large burst of low-quality, non-authoritative, or bad-neighborhood links, though, can do a lot more harm than good; so keep things natural.
The importance of the URL is often debated, but one argument seems to make more sense than the others. Search engines don't like too many parameters in the URL (easy to confuse the spiders with & and ?) and people can't read those long URLs and tell what they mean at a glance either. The people aspect here is especially important, because they're the ones clicking and they need to understand where a link leads them at a millisecond glance. Lesson: keywords in the URL are a good idea.
6. Spider Food
Search spiders eat HTML, not Flash. They eat text, not pictures. Make the spiders happy with HTML and lots of text to eat.
(This is why I design exclusively in .html and use Flash elements sparingly, if at all.)
7. Site Architecture
There's a lot to consider here, but the goal is creating a site spiders can easily access, a site that tells them where to go and what to index. Sitemaps are vital for this purpose, as is proper use of Robots.txt.
8. Frequently Updated Content
You could start a site, slap some content on it, and let it sit there in cyber space. It'll be indexed, most likely. But you really expand your credibility as a devoted, relevant source if you update regularly. In addition to spiders, it gives people a reason to come back, too.
9. Start a Blog
A great way to establish yourself as an authority voice on the Internet is to start a blog about the industry you're in. Maintaining a blog means another entry point with regularly updated content that eventually with some authority helps pull up the main site via targeted links to the site, or specific pages within the site. It's not a spam blog, which will be zapped eventually, if there's useful content on it and legitimate linking.
10. Don't Forget Humans
This is so important, it probably should be higher up on the list. There's an art to designing a site that is friendly to both search engine crawlers and the people you ultimately want to convert. Without people, what's the point? So first design for them, and then tweak to please the spiders, not the other way around.
SEARCH ENGINE OPTIMIZATION, THE MOST IMPORTANT ELEMENT!
Search engine optimization, or SEO, isn't a manipulation game— all search engine robots/spiders absolutely hate that game and will punish you for it. Good, SEO is made up of smart, user-and-search-engine friendly techniques. Think of SEO as a performance-enhancing drug—one that won't get you kicked out of baseball.