Can you explain certain rules which you follow in doing link building?

Hi Friends,
I use many specific rules to define the quality of links. I will look at following factors before submission :

• Quality of back link(PR, PA, DA must be good)
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  Relevancy of the content between 2 sites
• 
  Proper use of anchor text.
• 
  Avoid site-wide links
• 
  Avoid links from low-quality sites.

Rules which i follow are following
a) Ask for backlinks
b) Build relationships. For good link building
c) Give a testimonial
d) Start a blog
e) List your site in trustworthy directories
f) Write a good guest post