Construct things that deserve continuation.

Continuation is expensive. Someone has to care enough to maintain, defend, and keep improving a thing after the excitement has gone. Only things with real, durable value earn that, which makes the question of whether something deserves continuation a useful filter before you start rather than after.

Ask whether you would still want this to exist in ten years if you had no involvement in it. If the answer is no, that is worth knowing now. If it is yes, build accordingly.