1- Quality of Backlinks – The quality of the website linking back to your site matters the most. If you are receiving a backlink from high quality and trusted websites then your chances of gaining authority is higher.
2- Relevancy of Backlinks – It is important to get thematic and relevant links to your site. If your site is related to music then get links from sites that talks about music, songs, albums, films etc.
3- Naturality – Links gained by your site should come in a natural way and must not look spammy. No similar anchor text backlinks, reciprocal links, purchased links etc.
4- Frequency – The frequency with which links are build to a website also matters. If you are building too many backlinks within a short period of time then your site can come under the scanner.
5- Quantity– The more high quality links you site is having, the higher are your chances for ranking better in the SERPS.
Now, have a look at this amazing infographic which shares the link building basics you must follow in 2013.
Also See:-
How to Plan Your Link Building Strategy?
Link Building 2013
How to Create Backlinks that Google Loves
Seo Secrets
How to rank in Google
Google Disavow Links Tool