The thing that has eluded me is how to make a pin go viral. Something has to set them apart, make them stand out... Below are some steps to help you gain success.
Joining group pin boards is always a great idea. It gives your pin a chance to be seen, and hopefully shared, buy those in the group. Set up your own group board or join ones you like. The cool thing about group boards is that when someone pins, everyone in the group will get a notification. It draws interest to your pin and hopefully they will re-pin.
Reminding yourself to schedule pins is a practice that's good to get into. For example, take the amount of groups you're in and divide that number by three. You don't want to pin it to all your groups at once so try and schedule yourself to pin it to "x" amount of your groups on day one, "x" the second day and "x" the third day. That way the content is staggered and fresh to be repinned. Exceptions include pins are are event/holiday specific. Those should be pinned at least once a day, staggering them through your groups for at least two weeks before your event/holiday; that way people have plenty of time to stumble upon them and re-pin.
If your pin is a project that pinners feel they can complete easily, the more likely it is to get pinned. "How To" tutorials & recipe posts are always a huge hit as well. Make sure your tutorial/recipe is easy enough to follow, meaning that they should be able to complete it without too much effort.
Make sure your pin tells a clear story. If it's just a random photo, people are less likely to re-pin it. Draw the pinner in with pretty graphics and a clear discription of what your post is about.
Building friendships with other bloggers is helpful not only to you, but to the people you befriend. Blogging is a community so join in on the fun! Make blogger friends. Help them out & they'll help you.
As each blogger or pinner is different, you might need to adjust these steps to find the right balance for you. Since I began scheduling reminders for myself, I've seen a good jump in traffic to my blog from Pinterest (it's always a little bit thrilling to get notifications that your pin has been repinned, amiright?).