Getting forums to rank for their niche?

Hey guys,

New here... long time internet marketer and forum owner (since 1997) who has since become complacent and now i am paying the price. Things are changing so fast these days, and I have not done my part to keep up with it all. So that's why I am back on this site hoping to do a little catch-up.

Anyway... the main reason for this post is that I would like to get your opinions on getting forums to rank for the niche that they are in. I have always done well with this in the past, but now I run 2 forums (both the only forums in their niche) that consistently rank BELOW less relevant sites on google.

I think it really comes down to keyword density but I am not really sure. While my forum might be about "selling mary kay cosmetics" (hypothetical), and every single post is about selling, how to sell, what to sell, etc.... from over 10,000 members..... I am still outranked by simple blogs of 20-30 pages that might for example, teach you how to get into selling mary kay.

I am open to any and all suggestions. I am not sure weather to focus on backlinks, keyword heavy articles, or what to do at this point. IMO these sites are number 1 in their niche... should be at the top of google but they are not.

Thanks in advance for your feedback!