Sometimes a design demands a “zero” or very small radius inside corner. This can be completed at minimal cost by designing a “pilot” hole.  The rest of the machining can still be completed with large high speed cutting tools.

When designing a part for high volume manufacturing add “machining locators”. These are added to castings/forging/extrusions or can be added to parts machined from billet in the first operation.  Through the machining processes they are used to “hold on” to the part. The can be cut off if needed in a final operation.

When designing a part with threaded holes attempt to make other non-critical holes use the same size as the tap drill.