Custom parts
Protect the function. Simplify everything that does not contribute to it.
Start with material and stock
A common grade and a stock shape close to the finished part can reduce cost. Removing most of a large billet takes time and wastes material. Choose strength or temperature capability because the application needs it, not because a material sounds more advanced.
Reduce tool difficulty
Increase inside radii, shorten deep cavities, and standardize hole sizes. Avoid small deep slots, unnecessary undercuts, and overly long threads. A minor geometry change that permits a larger, more rigid tool can be more valuable than a small reduction in finished part volume.
Reduce setup and inspection effort
Group features on accessible faces and provide good clamping surfaces. Apply tight tolerances only to important fits and locating features. Define requirements clearly so the manufacturer does not need to price ambiguity or repeated clarification into the process.
Order the right batch
Setup cost is shared across a quantity, but inventory still costs money. Validate new designs before ordering large batches. Compare the total project cost—including redesign risk and unused parts—rather than pursuing the lowest unit price before the geometry is proven.