Mistake 1. Keyword Flooding

The Error: Trying to optimize a home page for all possible keywords. For example, you will often see "title" tags loaded with 12-plus keywords. Here a webmaster is attempting to squeeze in all his keywords on the home page -- classic example of how a little know-how can be a dangerous thing.

What generally happens is that none of the 12-plus words ever reach a high ranking because individually, they can never get the density or repetitions needed in order to rank highly. This is especially the case for popular terms. I laugh when I see spammers hiding loads of keywords in long lists, knowing that rather than improving their rankings, they just make them worse! Less can mean a lot more when it comes to search engine optimization in this respect.

The Solution: Focus your home page for a maximum of three of your top keywords. If you're in a particularly competitive field, then make that just one or two keywords. Concentrate on just those keywords on your home page and, of course, in your title tags.

Summary: Focus on your top keywords (hopefully researched properly) for your home page, and keep them to a maximum of three. If you are really in a niche market with little competition, it's OK to go up to four or five. Try to keep your title tag to less than seven words, and make sure your text copy uses the three terms at least three times each. Don't forget that every page is a potential entry page from search engines, so there is no need to cram everything onto your home page.

Mistake 2. Header-Area Duplication

The Error: One of the most common mistakes, yet devastating for search engine traffic, is when a webmaster uses "save as" to work on a new content page but forgets to change the nonvisible header area of a page in Dreamweaver or whatever content management system is being used.

I think we've all seen these sites. A whole site has something like "widgets-for-sale.com" in the title on every page: the meta tags are identical on every page. Only the visible content is different. Rarely, however, do separate pages have exactly the same theme or content. Every page can be optimized for different keywords, whether major or minor, and can be an entry point to your site from a search engine. It's such a waste when I see great sites using mydomain.com for a title on every page.

The Solution: When developing a site, stick to a pattern. I will normally do the content first, but I always make sure the last thing I do before moving onto a new content page is to make sure I have optimized not only the content, but the area as well. You won't find an identical title tag on my whole Web site, or a meta description for that matter. Never forget that each page is an entry page, and optimize each one to the best of your ability.

Summary: Never repeat titles or meta descriptions in a Web site. Treat each page as if it were the most important and optimize it thoroughly. Don't be tempted to leave the head area without optimization.

Mistake 3. Unnecessary Frame Sets

The Error: I rarely see framed Web sites anymore, and I believe in using frames only when they can enhance a site or are a practical necessity for a development. It isn't so much that framed sites generally rank lower; it's that few webmasters know how to correctly optimize them. This might give you an idea of the scale of the problem. The majority of those million-plus Web sites require search engine optimization. Not many of them are going to rank in the top 10 of anywhere. Just to have browser+does+not+support+frames" in your noframe tag is a great way to never get your Web site found on a search engine.

The Solution: Treat the noframe tag content as if it were a text version of your home page and optimize it as you would a normal Web site. Very important: Also link to your framed pages from your noframe area. For your framed pages, consider JavaScript that will call the frame set should it be found orphaned in a search engine. Normally, framed pages without the frame set mean no navigation and aren't displayed as was initially intended. The following code placed in all framed pages is one solution and works on the majority of browsers:
<"BODY onLoad="if(parent.frames.length==0)top.location='http://www.yoursite.com/frameset.html'>

There are more complex and better solutions, which wouldn't really fit in the space I have here. Try NetMechanic for a more complete solution. Also be aware that you can achieve what a frame set does through the use of cascading style sheets (CSS) layer positioning, iframes and other methods. Use frames only if you really, really have to.

Summary: If you must use frames, make sure you optimize them well. Use the noframe tag properly, and thoroughly link to framed pages. On your framed pages, use JavaScript to prevent them being called
without the frame set.

Mistake 4. Splash/Flash Sites
The Error: I often see poorly ranked sites that visually contain a lot of text, but the text itself isn't of the font variety but is a graphic. Great "eye catcher," but forget a high ranking and search engine traffic if that's the only text on a page. I would say at least half my clients used to suffer from overdoing graphic text. The main webmaster culprits for this are (surprise, surprise) adult sites, as well as those targeting young markets, where it's believed lots of graphics and eyecatcher's are what impress and sell things, such as games console Web sites, games software sites, etc.

Of course, the worst of all has to be the Flash Web sites that offer no pure HTML.

The Solution: Integrate normal text where you can. You can make text and text links look great with a bit of CSS formatting know-how. You don't need graphic text to make text look attractive nowadays. At the very least, don't make your pages all graphic text. Leave something for the search engine spiders to find and index. This also applies to Flash sites. Rarely does everything have to be a flash object. You can quite often have text surrounding a Flash object without any negative effects.

Summary: Web pages that contain no normal text, or very little text, simply won't rank highly unless there is a very strong link campaign running. Mix graphics and objects with text. It's really this simple. Remember: No text = no ranking.

Mistake 5. Keywords Not Researched

The Error: Unfortunately, too many webmasters don't really bother using any of several keyword research tools -- there are about four or five of them. Most, like the Overture keyword research tool, are free. Many webmasters don't think they need to use them because they know what their sites are about and don't need to research the top keywords. This is a big mistake. Another big mistake is either optimizing for too niche or too obscure a search term, or going the other way and going for a very broad term. You either get too little traffic because you optimized for terms that are rarely searched for, or you go for the terms with millions of competing pages but you don't yet have the experience or incoming links (one element of off-site optimization) to be able to compete.

The Solution: The balance is normally achieved through two- or three-word phrases in competitive areas. These are best found by cross-referencing the several keyword research databases.

Summary: Don't guess your best keywords. Know them through taking the time to use the free tools out there.