On the first Saturday of every month, take a photo approximately every hour and share on Instagram with the #1Day12Pics hashtag.
Using hashtags to get more followers is an art. You don't want to pick the tags with a million posts, and you don't want to use ones that no one will see. Your best bet is to pick the mid sized hashtags that have an engaged following. This is a list of hashtags for general blogging, and then divided for fashion, design, food, travel, craft and beauty bloggers. There's also a general photography list.