A lot of the time website owners are gaining good rankings dispite there efforts rather than because of their efforts. To give website owners a good foundation to learn from I have outlined the top ten mistakes I see most often.
No means of measurement
To truely know that you are making improvements you need a means to measure it by!
Best means of measurement
No finish line
How can you know what success is if you haven't defined it from the start. You wan't to start a SEO campaign with a goal in mind from the start. Be clear and realistic, but define it before you start.
For example. You want: A 30% increase in Search views, 10% increase in Click through, 20% increase in Traffic, 20% reduction in bounce rate, 10% increase on sales figures from last year. To be achieved within 3 months. Budget of $3000. Expected total profit increase of $10,000, with a net of $6000.
Try to juggle everything all at once
Making big changes for many things all at once is a recipe for confusion and mistakes.
Unless obviously wrong or missing, make changes slowly and in a measured fashion. Remember you may not see the fruits of your labour in the search engines for weeks or months. So give it time to take effect before you make more changes. When you have everything right then go for it.
Generating traffic for a grave yard
What I mean here is - Make sure your site works first. Make sure you have all the basics covered first. No point driving people to your slow slow site which crashes under the slightest load. Worst still one with a poor checkout, that only meets 10% of the market. Gear up for traffic first, then go get it.
Not working with the clients or search results you have first
Try not to concentrate on one source of traffic
Things change in business and banking everything on one source of traffic makes no sense. Yes some sources will be better than others. However try to gear your business towards organic search first, then manage many others along with it. Yes the most effective/profitable should get the lions share, but try not to focus solely on one. The reason for this is things change fast online. One day adwords can be king the next a money pit.
Copy pasted content
While I am a realist and realise for most business there can only be so many ways you can write 'truely original' content for house cleaning or car sales. If you can put some flair into your content to make yourself standout. Do not copy and paste from other sites. Duplicate content will hurt you. If need be run it through a plagerism checker.
There is a limit
There is a limit to keyword stuffing. While it isn't to clearly defined if you are worrying about it your probably way over. You don't need url links like johnswidgets.com/widgets/widgets-australia-widgets-blue/ . As a rule try to be description and explicit with your content and links. Stay away from reputation. Having widgets once is more than enough. Saying widgetwidgetwidget means no more than widget and possibly less.
Be explicit where it counts
If your selling a 3.2meter cable call it a 3.2meter cable. Your it in the url, title and description. Your more likely to capture a search result with a more explicit description than and general one.
Multiple domain names pointing the same site
I have been seeing this a lot lately. I am guessing it is due to very old articles still floating around. Don't do this it is a was of money. It might have worked 5-10 years ago, but it doesn't work now. All you are really doing now is watering down your content and confusing the search engines. Yes you do need to declare it in your side code if you do need to do it. However that also negates any SEO reason to do it.
Concentrate on your main domain and no other.
Taking advise from old articles
You have to start your learning process somewhere. However keep in mind with SEO what ever was working 12 months or 6 months ago can often be over. Google and Bing are constantly looking for ways to stop SEO experts gaming the system. Check your source and the date it was relevant. One of the best places for info is Google.