to fine-tune a design

Is there a Greek expression for when an architect wants to "fine-tune" a preexisting design for a building as in the process of taking a design that has already been established and presented but is taken to its final level of refinement?

Ideally a colloquial phrase ... please:)

Βελτιώνω
Κάνω μικροβελτιώσεις ή προσαρμογές
Τελειοποιώ