Reuse and recycle your best content. Look at your statistics - I use Spreaker to distribute this podcast - Spreaker statistics are awesome! You can see popular episodes and your most listened to shows. Retweet, like and share your audio again on Google+ to gain new listeners and boost old content. It's work you've already done so make use of it again and again.

I recommend Buffer app to help you schedule tweets at intervals you choose on Twitter: http://jngl.es/buffer