Curious what Physical Tools/Props and digital tools everyone uses. I'll go first.
VTT: Dndbeyond maps and Owlbear Rodeo
Audio/Video: Discord with Avrae
Notes, Lore, Session planning. Google docs with Table of Contents for NPCs, Session Notes, Plots, Characters, Magic Items, Locations, Factions, etc.
Idea brainstorming: Everything. Occasionally, if I need to somehow fit ideas together or something out of left field, I use chatgpt, but keep in mind, chatgpt is highly repetitive and can often times use a lot of words to say nothing.
Encounter creation: Kobold Plus Fight Club or Dndbeyond.
Advice or collaborative discussion: Here or reddit.
Guides for Character creation for new players: rpgbot.net