A great way to promote your podcast is in other podcasts. It's what's known as a "Feed drop." If you can work out a trade with a similar podcaster, you can promote each other's shows. The old adage is "fish where the fish are." It's a lot easier to land a podcast listener from another podcast than it is from a social media channel. They're already on their podcast app!
With that in mind, here's a demonstration of how that works. I'm working on another project - a podcast commemorating the 50th anniversary of my college radio station in Syracuse, WJPZ. Episode 1 of the podcast debuted today, with interviews of our longtime faculty advisor, Dr. Rick Wright. I've taken the artwork and audio from that podcast's trailer, and added it to my feed for my followers to see and hear. And it's up now, classified as a "Bonus" episode. Maybe you'll be interested and follow that show after hearing it here. Enjoy.
Here are some great episodes to start with. Or, check out episodes by topic.