>>29525775They're both pretty smart, you could have a how to social interaction and etiquette episode, a trip to Canterlot, using Twilight to influence ponies and have leverage until she gets fed up, Rarity finding a magical artifact while gem hunting, Rarity being overwhelmed by dress orders and using Twilight's managerial skills to stay on track, or just 20 minutes of Rara and Twi visiting the spa and going for a coffee while talking about their days.
I'd love the last one. I want the most slice of life comfy episode possible with those two, so much that everyone on /mlp/ would shitpost how boring it was. It would be perfect.