A custom application should make a real workflow easier to run. That starts with the roles, decisions and records involved, before a screen is designed.
Model the work before the screens
Name the roles, decisions, records and lifecycle states that make the process real. This prevents a polished interface from hiding an incomplete operating model.
Separate the first release from the wish list
A first release should complete a valuable workflow end to end. Secondary reporting, automation and edge-case tooling can follow once the core path is proven.
Make trade-offs visible
Document what is in scope, what is deferred and which assumptions still need evidence. Clear boundaries protect both delivery speed and product quality.
Working principle
Release one complete workflow before adding secondary features.