How do I create a custom form?

I do the following a lot, with images in the user profile for instance:

  1. Basic / Image_Submit
  2. Generate image column (mesh or triangle) / Image_Default
  3. ITE column / If Image_Submit is empty then Image_Default else Image_Submit

@Robert_Petitto has a more advanced version than this on creating fun default avatars using the color palette column.

Boring avatars