Best free ways to promote a blog?

There are many different ways to promote a blog and drive traffic. Here is a list of things I do for promotion. I hope it will help you.

Social media optimization works best for my blogs. Use sites like Facebook, MySpace, Twitter, Digg to promote your content. Create a community, join similar communities in your niche, participate in events and you will get people attention. Groups and communities in your niche work best. Also social media sites in you niche may bring you more visitors than big, global SM sites. For example, for one of my coding blogs I get tons of traffic from DZone – social bookmarking site for developers.
Offer social bookmarking buttons to encourage your readers to share what they like. Tweet and retweet buttons also can bring you many new fans.

Link building.
Link building is an essential part of a SEO campaign. Don’t skip it. Join the majority of blog directories and especially the ones in your niche. Share some personal information and write something interesting as a description of you blogs.

Press Release Sites – write a press release and send it to some of the biggest press release sites. If you have a specific niche like gaming – send your press release to the biggest news sites in your niche.

Register to search engines. It may sounds trivial but this may help you a little.

Run contest or offer something for free. You can offer an e-book, website template, or blog theme. Freebies tend to bring a lot of new visitors.

Forum posting and blog commenting.
Prefer forums and blogs in your niche. It would be better if they don’t add nofollow to your link.