Everyone has done a great job listing ideas. For me, SITS, blog hops, and just commenting on others has helped. But at the bottom of it all, you have to have good content that people are interested in. Not everyone, but at least some. I primarily write about Autism and living with a son on the spectrum. So naturally, I have a lot of followers and commenters with children with special needs.
I comment and seek out new blogs to comment on at least once a week. I see a bit of traffic from that. I also am pretty active on Twitter and get about half my traffic from there. I am also active in a blogging community Momdot. I always find new loyal readers by being active in communities. Updating my blog and adding quality content seems to be the best way to increase blog traffic. (for me anyways)
Work hard to create great content that my readers enjoy and is good for SEO. According to my stats I am doing OK with my SEO but I trying to get better.
Comment on other blogs. This is time consuming so I only get to do it 1-2 a week. And I leave genuine comments not just "nice post" ya know.
I also try to be involved in forums like this. However this is also time consuming so I usually pick forum each day. Because if I am not careful I could spend hours without even knowing it.
I have a facebook page and twitter, I don't have many FB fans (would love more ;)) but I definetly get a lot of traffic from twitter. According to my google stats about 20% of my new unique visits are from twitter.
I also use stumble upon. This hasn't been too successful for me yet because I just started. And I don't think a lot of people in my niche use it. But I always try to stumble people if that have the stumble button.
I am involved in friday follow meme. It is a great way to increase numbers if that is what you want. I have found some loyal readers through that However I think to find more loyal readers the others have helped me out more.
When I first started out I was all about the numbers but now I focus on quality of quantity.
I make friends in tagged.com. You need to be worry, as a women automatically you will get 100s of request a day. then post your blog url in bulletin so that it reach to all your friends.Eventually you will get 100 of visit if you have 1000 friends.I used it for my squidoo blogs http://www.squidoo.com/cougar_dating http://www.squidoo.com/dog-world - this one is new blog but anyhow i managed to get views from pet players.