PD Budgeting: How to Account for Alteration & Prep Time?

Hey everyone, Brianna here. I'm working as a Casting Associate on a new indie feature, and we're trying to refine our production budgeting process. I was reading through some general advice, and a common mistake highlighted was underestimating the labor involved in alterations and prep, especially for props and set dressing. It's often this hidden time that throws things off later.

From a PD's perspective, what specific line items should be explicitly included in a budget to accurately account for this? We've typically lumped 'prop acquisition' or 'set dressing materials' into broader categories, but I'm realizing that doesn't really cover the hours spent custom-building, painting, distressing, or modifying items once they're sourced. I'm trying to help us build a more realistic plan from the start.

What are the most effective ways to budget for this 'hidden labor'?