For brainstorming, collecting and sorting ideas I use

- either the outline feature in Word or Textmaker (Word is better for moving items around)
- a visual tool such as Milanote or Miro so I can share the map with colleagues or customers. I used to use Scapple but it's single-user, and the Windows version appears to be buggy (maps I create on one Windows system look different on a second machine).

What never really clicked with me are mindmaps.