So now that we know the experts can't agree, I might as well tell you the mistakes I've made plus the ones I see done by many Webmasters when link building.

Failing to Procure Reciprocal Links.
I've seen so called SEO Guru's say that reciprocal linking is dead and they will hurt your site. This just isn't so. The important thing to remember is to make sure the links you trade are from quality sites. It doesn't matter if they're PR0, just make sure they're not from a spam/ adult/ pharmacy/ hate type site. Reciprocal links can be on a resource page if you run a website or a Blogroll for you bloggers. Just remember to trade!

Failing to Acquire Low PR Links.
For some reason, many Webmasters do not want PR0 sites linking to them. This is link building suicide! One day, those PR0 sites could be the next PR5 or better. Frankly, I don't care who links to my sites. I can't control it and if they're passing any amount of authority, and even PR0 sites pass some, I'll take it. It also looks natural when you have many more low authority sites pointing to your site than all high PR sites.

Failing to Link Out.
Once again, we're talking about making your site look natural to the Search Engines, especially Google. Authority sites link out to other authority sites. Google expects to see this. I can't tell you how many times Ive had a site stuck in the SERPS only to get a little boost when I linked to a higher authority site. So link out to authority sites!

Failure to Check Your Reciprocal Link Partners' Websites.
Once you exchange links with someone, you need to follow up on a routine basis and make sure the link back to your site is still there. Some sites go down, accounts are closed, domains expire and are purchased by someone else, Webmasters change website topics and some Webmasters simply take your link down after you exchange links. I've seen people put the "nofollow" attribute on the links after they've made a trade. I've seen it all happen, that's why I monitor my link partners and you should also.

Failing to Use Anchor Text in Your Link.
If someone gives you the opportuníty to use Anchor text in the link back to your site, use it! In my opinion, anchor text in a backlink is the second biggest off page ranking factor for SEO. Only the relevancy and authority of the page where the backlink originates is more important in my experience.

Failing to Cover Up Your Paid Link Footprints.
Look, from here to the end of time, people will sell links. And from here to the end of time, Google will be trying to find paid links. And from here to the end of time, you'll see blogs, websites and blog networks (think Backlink Solutions) get de-indexed for selling links. If you're going to buy or sell links as part of your link building plan, you'd better be hiding your footprint or Big Daddy G is going to find you one dark, cold and stormy night. There are several ways of hiding your footprint, I covered one way in my link laundering article a few weeks ago.

Failing to Build Links.
I see people on the forums all the time asking how they should go about link building or how to get started link building. Many say they don't know how and so they don't even try. People! I hate link building as much as the next person, but it's not Rocket Science. You may be able to rank high in a low competitive keyword niche with on-page SEO, but for a competitive niche where's there's money to be made, you're going to need some relevant backlinks!

TIP: One of the most effective link building strategies you can perform is to find out who's linking to your competition and get links from them. You simply go to Google and type in link:yourcompetitorssite.com. You'll then get a líst of sites that are linking to your competitor's site. Browse that site to see if there is a place to put a link to your site at. If not, simply Contact the person running the site and ask kindly for a link. Many times they will not respond, but some will. Now, out of those sites, do the same thing. See who's linking to them and get links from those sites!

This is probably the easiest way to get relevant backlinks but it's a technique very few Bloggers and Webmasters use! Sure it's tedious and time consuming, but in the long run, those top rankings will be worth all the time you practiced link building!