What brings me the most traffic to any of my blogs is search engine referrals, mainly google search, I used to get a lot from MSN but not so much these days and I have never really got that much attention from Yahoo search, I really have to look into what's up with that, I shouldn't really be relying on only google for traffic, especially since changes seem to be on the horizon.
The best advice I can give you on ranking well on google is to do your keyword research, figure out if the term you want to use is highly competitive, if it is able to send you significant traffic, write a nice post, keyword rich, and try and get some nice link backs to your post using the keywords, phrase you used for your title.
I use this tool to roughly gauge what kind of traffic I may expect from my keywords, something in the 30,000 searches a month would be highly competitive, something under 1000 is likely not and should be easy to take out, all you need is a few good back links with good keywords, but I only do this if I feel I can add more to what is already there with a post, that's mainly why I ain't rolling in traffic, but over time with multiple posts taking out top results the for low traffic keywords, the traffic will eventually build up.
It's easy, it works, but it takes time to build up. Unless you got a huge following of bloggers and such to spread you link like wildfire and have must see content, aiming for high traffic keywords is a dead end.
Though with all this change talk about google I may have to start thinking about MSN and yahoo.