There's a really great article over at about how to be a Reddit power-reader and create custom multi-reddits. From there you can share via buffer via the buffer browser extension or just get the url of your subreddit and add a .rss extension and get the feed from it. Disclaimer: reddit switched from RSS to Atom in January 2016, but they kept the .rss extension. I would've liked them to maintain the rss and just added a .atom extension, but I don't work there.