Networking, joining places like this and Entrecard, Twitter and such, you find a ton of new faces, new people and new friends.
Something that someone told me that I didn't realize is keeping your face recognizable. This photo on my avatar has been with me from the beginning and it just makes you memorable as well as your blog name. Just a tip.
I've had great success with hosting giveaways / contests. I also feature other moms once a week. When a mom is featured - she tells her friends and they come read...it might be once, or they might subscribe if they are interested in what they see. It never hurts to share the love :)
I'll agree that doing a giveaway brought a lot of traffic to my blog, although very few stayed. I think finding like-minded bloggers is important. Not only do I go through their blogrolls and visit the people they like, but I click on many of their commenters and find even more people I can relate to. These overlapping networks seem to grow on their own.
Without a doubt, you have to visit, read and comment on other blogs. That is the first step to developing relationship with fellow bloggers. Throwing your URL around a lot is basically a form of spamming and can actually do your blog more harm than good. But if you give value to another person's blog by leaving thoughtful comments, you'll see your efforts reciprocated.
Where I have met some of my best bloggy friends is right here at MBC, loyal and very friendly! Entrecard is great for discovering new blogs and Twitter is really good also, but provide your link every now and then.
I've never done the whole EC thing, even though I've thought about it a million times. I'm awful at Twitter--I think my last update was 2 months ago! I know you said "besides visiting other blogs and commenting" but really, that's what has gained me all my readers:)
I've done some networking and have my blog listed on several blogrolls...however, it can still get lost in all the other wonderful blogs on those lists. I think the best mode of traffic is to go out and meet other bloggers by commenting, and encouraging. What blogger doesn't like to be encouraged. Even more, I try not to leave a general comment like, "great post! I agree". I try to be personal and specific. This really tells the person you actually care about what they wrote rather then getting a recipricol visit or comment. :)