Links should be relevant
If you’ are a solicitor there is not much point being linked to and from "wrestling" websites. Always Be strategic when linking. In general, the fewer the links the other site has the better. If you’re just one link among a long list of links, there’s not much as much value there.
Get linked from Web sites that are also well linked. The more those other Web sites are linked to the Web site that is linking to you, the more valuable a link from that site is.
Get links that reflect how people search.Let’s say that your customers search for "New York Real Estate". If you can get links with that exact phrase, the chances of you being found during those types of searches will increase.
Refrain from changing the structure of your Web site.If you change the structure, you risk breaking incoming links. If you do make changes, have a "404 Error" page that becomes available when visitors visit these "missing in action" pages indicating a particular page is no longer available. This page should contain links back to your site.