Hi,
There is nothing like so many links must be built per day to be effective from an SEO standpoint. Links from high domain or page authority that are acquired naturally through quality content can be very powerful. Aim to add high quality, uinique, fresh and highly relevant content to your website. Content of this sort is a natural link magnet. You will see good, volutary backlinks heading your way over a period of time. Also try to do content marketing with again good quality content to acquire desired results in search engines. Never use automated tools to build your link profile. Use tools to find the sources for your link building campaigns but never use tools to automate the link building process itself.If you want to divide the backlinks based on their importance, here you go:
Pristine quality links: Links from authority websites in your niche
High to Pristine quality links: Links from generic authority websites like Wikipedia
Medium to High quality links: Links from websites in your niche that are not so authoritative
Low to Medium quality links: Links from generic websites that are not so authoritative. For example, forums, blogs,
Low quality and Spammy links, the ones you should avoid: Links from completely unrelated web properties, link farms, sitewide links like footer links etc, blogrolls, excessive link exchanges, cross linking, think affiliate sites that have no substantial content, porn or gambling (unless you operate in those niches), web properties operating in illegal trades etc.
Build or rather acquire links gradually and never indulge in desperate or hasty link building tactics.Your link profile should have a natural and steady growth more or less with good diversity in anchor texts.
Hope that helps.
Best,
Devanur Rafi.