I see people all the time talking about creating NF and DF links so that it looks like a more "natural pattern" to google. I don't think I buy it. Not even one of my sites has a natural linking pattern (I work with over 40 sites). All of them are extremely top heavy with DF links. Most are auto approve. I don't do link building on a regular basis, it is VERY spiky! I have more high PR links then could possibly ever be gotten by luck alone... It seems that I do everything wrong when it comes to link building, yet just about all of my sites are on the first page of google for their search terms. The only "law" I hold myself to is that I don't allow myself to create anymore than about 30% more links than my closest competitor. I have never tested this (just a self imposed rule), but my gut feeling is that there is some magic formula for each keyword as far as the number of links there should be before it triggers some additional filters. I don't know if thats accurate or not, but I do know that 30% above my closest competitor has always kept me safe and it still gives me a significant bump in link totals compared to everyone else. So, I personally get tired of hearing the "natural link building" term... don't know if anyone else has experience with this differently, or if this is just one of those terms that sounds reasonable, so it must be true and we all recite it!