In general, I take my main money site and create from 25 to 90 web2.0s pointing to it. These are my "buffers". I'll blast that list of 25 to 90 with wiki links, with AMR blasts, outsourced scrapebox and xrumer blasts, and social bookmarking. How much generally depends on difficulty of keyword.
To my main site ... if it is less than 6 months old I just do the web2.0 buffers and linkpushing.net. If the site is over 6 months old, I will do web2.0s, linkpushing ... and throw in direct wiki links blasts, direct AMR blasts, direct social bookmarking.
I try to maintain an even link velocity, and I go around 25% exact keyword anchor text I want to rank for, 50% anchor text that contain my keywords but not in exact keyword combo I want to rank for, and 25% completely random links like exact URL, "click here", "this site" and such.
If the keyword is 20k exact or more and seems pretty difficult after time, I'll set up additional web2.0s into tier 2 and tier 3, supporting the original web2.0s.