When Janay built Prompt Arsenal she did not start with a features list. She started by watching herself lose prompts for two weeks straight and writing down every single time it happened. That list became the entire first version.
If you are trying to build something and do not know where to start, stop guessing at features. Track your own pain for a week. Write down every time something annoyed you enough to think there has to be a better way. That list is your build order.
Where are you in building something right now? Drop it below.