Here you will find various resources and tip and tricks for portable ops useful for MSPOTA
Practical NVIS Antenna for Portabale and EMCOMM Operations
Antenna Toolkit 2nd Edition
EARC END FED 6-40 Meter Multiband HF Antenna
Working The EARC End Fed 40- 6 Meter Antenna – YouTube
Successfully Operating a Portable Amateur Radio Station: Reactions of NPOTA Activators
Learn how to build a NVIS Antenna (DX engineering)