Jokes aside, I’m not the best disc priest, but generally you want to hit Power Word Solace off CD, and try to be as mana efficient as possible.
I generally like playing without radiance, but its not too feasible whenever you go up against bursty teams. You mostly aim to rotate defensives pre-emptively in something like dome>rapture>ps>dome>rapture I guess but games can vary depending on what happens (you get stunned into everyone popping offensives so you ps first and pray you dont have to trinket). I always like to play trinity/darkarch/dome but its hard to pull it off successfully.
(edit) so instead of trinity/darkarch/dome you’d opt to play trinity/ultimate radiance/dome or trinity/ultimate rad/dark arch if you don’t think dome will have as much use (but imo you always do)
Not sure if ticki made a newer guide but:
https://docs.google.com/document/d/15Gd9MFtuc57Gpk-ivkxXHyDGCZ4WkqT3LINcGnqmti8/edit