How do you vet overseas apparel/clothing manufacturers before placing a bulk order?

I've been on the supplier side of apparel sourcing (based in Hangzhou, working with winter clothing manufacturers), and I'm curious how brands on the buying side handle vetting before committing to a factory.

A few things I'd love to hear from this community:

- How do you evaluate fabric/material quality before seeing a physical sample?

- What's your process for a first bulk order — do you start small or go straight to full MOQ?

- Have you had issues with sizing, stitching quality, or delivery timelines from an overseas supplier, and how did you catch it early?

Interested in hearing how buyers actually build trust with a new apparel supplier, especially heading into winter season demand.