Post your mailing address on your website or blog and other places on the Net. If your zine is about doll collecting, post a blurb about it on doll collecting bulletin boards and websites. Do all the research you can about websites that feature similar material to what's in your zine, and then post away to distribute it.
Take copies of your zine to your local coffeehouse or alternative bookstore. The storekeeper may sell them on a consignment basis for you. Contact some of the larger chain bookstores in your region. Some of them occasionally carry small or homemade zines in their magazine sections.
Organize a reading to promote and distribute your zine. This is good advertising, but can also lead to better distribution as your zine gets more publicity.
Send copies to zine and magazine distributors. This is a hard sell if your zine isn't popular, but it's worth a try.
Get your zine reviewed by independent publications like Razorcake, blogs and websites. Double check before sending your zine, as e-zines and publications change addresses and go out of business all the time.