Some SEO mistakes are obviously far worse than others. If you know what they are, they are easier to avoid and that is the key. The following are the worst of the worst mistakes you can make when you are building a website in regard to SEO. it Is non-negotiable that you MUST avoid these mistakes associated with fundamental SEO, or risk what will be a lengthy process of seemingly never-ending fixes.
A big mistake in SEO is errors with title tags. The most common are using the same title tag for all pages (duplication), OR ignoring the opportunity to optimize them for the page’s keywords. This may actually be the most common mistake, and most of the time it is a mistake born of laziness.
Using the wrong title tags is a mistake that is so easy to avoid but made over and over again. The fx isn’t very hard, but it is a major waste of time and potentially money as you lose ground in the SERPs just because you started off wrong in the first place. Title tags normally show on the SERPS as a clickable link, so make them say what you want to appear. It only takes an extra minute or so to do it right, so take the extra time.
A lesser understood mistake are Robots.txt errors. Robots.txt errors disallow Google from crawling certain items on your site. When used properly, they are a good thing. The problem is, if you do it wrong your entire site will wind up being ignored by spiders and that is a major problem. If you are having indexing issues, this is often the first culprit that your SEO will look for. Make sure you have a crawlable sitemap for best results. if you do not have a indexable site map, it is like making a teddy bear with no stuffing.
You need to optimize your internal links just as you do your external ones. ignoring this is a cardinal sin in SEO. If your home page has PageRank, you can be passing juice onto internal pages as well. Take every advantage of your internal rank and send juice to your lower pages for maximum benefit. Ignoring this easy, but essential, tip is to simply give away positioning in the SERPs. Make sure that you and your SEO are on the same page with this.