This one I turned on gradient in the Paint Brush Tool.
This one I used the Clone tool, and set the source to "Maple
This one I rendered a grid, and then used the Smudge Tool with a
low spacing and a slightly larger brush.
This one I rendered a plasma cloud, and used the Erase Tool with
a square brush.
This one I used the “dodge” tool on the top and
left of a blue box, then used the “burn” tool on
the right and bottom.