From time to time, I browse around the internet reading CTF write ups for my own knowledge and to get ideas for challenges. Here's a list of CTF write ups that I found interesting.
[NDH 2016] [FORENSICS 200 – I’M AFRAID OF A GH0ST NAMED POISON IVY] WRITE UP via 0x90r00t.com
CyberThreat18 CTF challenge write-up - "Network A" via chrisdcmoore.co.uk
Google CTF 2016 – Forensic “For2” Write-up via rootusers.com
kaizen-ctf 2018 — Reverse Engineer usb keystrok from pcap file via Medium
ICS (Industrial Control Systems)
DEF CON ICS CTF via domaintools.com