Use interactive polls in your Instagram stories.
Note: You can not add a poll to a main-stream/regular Instagram post, only to your stories. This means that your poll will vanish after 24 hours. I quite like this as it means that there is a sense of urgency about getting people to vote. Unlike Twitter Polls, you can only give two options, but the ones on Instagram are editable.
Have you been using polls? I particularly like the new polls on Facebook business pages (with interactive GIFS and images). Polls are a fabulous way to get interaction on your page or stories.