Find out what works best for each platform and use that the most. Then to see success in reaching your goals, it's imperative that you're consistently posting often and that you learn how to use the native features on that platform - whether it's scheduling or analytics, the native features are probably much easier to use than learning an entirely new system. Finally, don't forget to engage with your users and constantly interact back with them. When they take the time to like, share, and comment, you should mention them, thank them, and call them out for being awesome. That's going to help them learn to trust you more, see you as an authority on the topic, and get the word out about your offerings faster.