If you want to achieve useful SEO back links then you must know the correct strategy to generate more traffic. Back links help to enhance ranking of webpage over search engine. There are few important aspects that you should take care.

Blog Comments – You can do blog comment over other top rank websites but you need to ensure that you are not spamming. Some high PR (Page Rank) websites accept comments later or if they find it spam then comment can be deleted. So it is important to ensure quality comment.
Forum Post – Forum posting is another method for back links. You can join high PR forum where you can answer their questions and leave your link. Forum post is one of the popular ways fir back links, but here also you need to be careful for your answers and never heart anyone’s feelings.
Newsgroup – For back link you can also use newsgroup option. It is a platform where users discus and from various location over an issue. They share their opinion to and it is similar to forum.

These are few tips that you can utilize for back links however there many other ways for back links, such as Article Marketing, link exchange and interlink of web pages. Apart form these tips you should ensure the quality not only the quantity. To achieve a better rank ensure quality content over your website. Content should be attractive and relevant to your website so that you can get better traffic.