This guide covers the best techniques and strats used in the Quest – 8 Stages category I know of (at both a beginner and advanced level).

Guide (pdf, A4): https://loup-vaillant.fr/tf/TF-quest-8-stages-guide-A4.pdf

Guide (pdf, A5): https://loup-vaillant.fr/tf/TF-quest-8-stages-guide-A5.pdf