In my experience this applies to every feature. Heh, I think it depends on the feature ;) Past the first few projects, you should have a pretty good feel for

In my experience this applies to every feature. Heh, I think it depends on the feature ;) Past the first few projects, you should have a pretty good feel for how long standard CRUD, user auth, email fun and other such things should take. Basically, the more experience you have, the fewer times you should need to sacrifice time for proof-of-concepts - but there'll always be a need for them :)