Good PCB design starts with following the rules. Understanding manufacturing design rules prevents delays and costly respins.

Trace Width and Spacing:
- Minimum trace width: 0.15mm (6 mils) for most fab houses.
- Minimum spacing between traces: 0.15mm (6 mils).
- Power traces: use 1mm per 1A of current.

Via Sizing:
- Standard via: 0.3mm drill, 0.6mm pad.
- Use larger vias or multiple vias in parallel for high-current paths.

Clearance:
- Keep copper at least 0.3mm from the board edge.
- High-voltage traces need more clearance: 1mm per 100V.

Following these basic rules ensures your PCB comes back manufacturable on the first try.