Couple screws spaced to fit the hanger holes on the back of the power strip is what i always use.
Servo tape for radio controlled cars can work for lighter weight strips but I wouldn't trust it over a sump or other open water.
I mount them to a board and put eyes on the top of the board to hang from hooks in the cabinet. Doesn't come up much but makes it much less frustrating working on organizing and changing timers and such.
Nails into wood (not just gypsum) or screws.
Fairly small heads so the holes in the PS fit. When the tanks were inside the house the PS were above them on the wall. Then I could plug in an extra pump for water changes.