Tech Pack Creation for Fashion Samples

I need a lesson on creating a tech pack for fashion samples.

Key Areas of Assistance:
- Design Illustrations: I need help specifically with this aspect.
- Type of Illustrations: Open to various methods, not limited to the usual options.
- Software Familiarity: I'm using an unspecified software for flat sketches.

Ideal Skills and Experience:
- Expertise in developing comprehensive tech packs
- Proficiency in various design illustration techniques
- Familiarity with multiple design software, including less common ones
- Strong knowledge of fashion design specifications and requirements

Looking for a detailed, step-by-step guide tailored to my needs.