Link Baiting

This is the single most important method. It has mainly to do with good content that gets links the natural way. To keep things simple in this guide I have decided that everything that makes people link to you because of the content on the page/site falls under this category of link baiting. You need to read this post I wrote on link baiting.
Comments: Pure white hat, recommended but sadly not very effective if not something real major.

Directory submissions/Link Building using directories

There are specialized SEOs and Link Builders that are doing directory submissions. There are 4 kinds of directories here: pay-for-inclusion, reciprocal required, free and niche directories. And there are of course specialists in each one of these. There are almost one thousand free SEO friendly general directories, a list of these and a submission service can be seen here. As for placement in reciprocal directories there are both brokers and non-brokers.
Comments: Cheap way to get many low quality links. Can take months before effect is seen. Deep links usually not possible. New edit and comment on this: since BigDaddy Google has been smashing and deindexed internal pages on a lot of directories, but the indexed pages still show a PR value even though they are deindexed. Keep this in mind and run a site: command or type the URL of the internal page in Google to see if the directory/page has been hit.

Link Exchange, 2 and 3 ways

The good old way. I link to you and you link to me. This is more useful if you have 30 or more sites as you can get and provide relevant links. Rule of thumb: you contact people, not the opposite. There are also Reciprocal Link Programs but I don’t recommend that.
Comments: Don’t overdue it …

High PR-subscriptions (Grey Hat?)

You can rent PR 5-9 text links at various places for various prices. Cheap places I had some very good success with: here, here and here.
Comments: Don’t get too many high PR links too fast, get relevant if possible.

Link-Vault

I am myself getting 200 permanent links a day from this program to 40 URLs, all with varied anchor. The links you get from this program are mostly footer links and other low quality links but the program is extremely powerful. Do not, I repeat, do not display Link-Vault ads on your most valuable web sites - that is a red flag, especially since BigDaddy.
Comments: Only negative is that the links are mostly footer and the relevancy is not that good, other than that it is great.

DP Coop Ads (Grey Hat)

This program gives you a lot of rotating temporary backlinks from mostly footers of sites. I have been using this program successfully to boost SERP ranks in Google, especially at the V7N SEO contest. This program is extremely powerful as well as dangerous and can have your site banned or harmed if you are not careful. My rule of thumb: maximum 5K weight on a single ad. At one moment I had 120K weight and I was getting many many thousands of links to more than 40 ads that I had.
Comments: Remember that these are all footer, irrelevant, temporary and with fast growth.

Linking from your own web sites

This is an excellent way if you have many relevant pages in the same niche.
Comments: Don’t interlink all, keep sites on different C-class IPs and avoid patterns.

Pay bloggers

You can post on the business section of webmaster forums stating that you will pay to get the blogger to blog about and link to your site. Example.
Comment: Good to get the word out. The blog post will over time be buried down in the blog structure.

Article submission

Write an article with links in the article and/or in the resource section to your site. Or pay somone to write these for you. Use specialist (example) to have these submitted to article directories such as this one.
Comment: Long term strategy, takes time to see effects. Can be good for traffic.

Search the SERPS and make offers. (Jim Boykins speciality)

Yahoo and MSN both gives some extremely valuable information in regards to backlinks. Both of the engines tend to list the site with the most link power first in a backlink query. Study and understand the following queries:

• seo linkdomain:seobook.com -site:seobook.com linkdomain:seomoz.org -site:seomoz.org -link:jimwestergren.com (MSN or Yahoo)
  = Sites containing SEO, that link to both seobook.com and seomoz.org but not to jimwestergren.com.
• site:jimwestergren.com link building (Google)
  = Which page on the domain jimwestergren.com is most relevant and has the most power for the query link building?
• site:jimwestergren.com (Yahoo)
  = Which page on the domain jimwestergren.com has the most power? Not always the home page and the list is interesting to see. You can do the same in Google if you find the right query, valid example.

Use both of the above examples in this technique and send off a nice e-mail on your link offer to the ones you choose.
Comment: Expensive …

Make directories and make the link submitter reciprocal to a site of your choice.

I use this on 2 general directories of mine. My directories are free but the link submitter gets his link featured if he reciprocal with my other site. I get about 10 links per week using this.
Comments: Irrelevant, certain percantage come from bad neighbourhood and not always from same language.

Write testimonials and reviews

Write and send a testimonial to your web host, web designer, web developer and SEO. They probably publish it at their site and if you are lucky they link to you as well. Send a review to your favorite sites and have your name and link at the bottom of it.
Comments: Time consuming …

Links under articles

This is a new method I developed myself, here. In the future I think more will start to use this as well. It enables to link builder to exactly specify which articles, the anchor and the URL of each link. Good for deep pages.
Comments: All same IP. Permanent. There are more ways but the ones above are the ones that I deem effective,

My Recommendation

Use a mix of all the above ways to get links but follow what you wrote down when you studied your link profile. Good luck!