Hi Aspen,
a terra cotta pot would be a nice idea for sure- those frogs really like to hide. Also, they become more "brave" if they have enough hiding spots. Live floating plants such as hornwort, pennywort, duckweed, frogbit etc. would be a great addition as well, as they provide shady spots (frogs don´t like bright light), help with maintaining a good water quality by consuming nitrates and the frogs love to rest on the surface hanging on floating plants. Fake plants don´t do anything for the water quality, but the frogs don´t really care as long as they have structures to hide in. Maybe you could replace them by easy-to-gro live plants like Anubias sp. or else or mix with live plants.
It´s great that you keep your frogs in a decent-sized species-only tank

I don´t see a heater- please keep in mind that those are tropical animals. The temp should be at a more or less stable 74-79° F. Cool temperatures or big day-to-night swings might harm them at least over the long-term.