I will just say what i have seen as something that passes most of there crap,
having an isolation transformer that is fused on the mains side and put to an IEC socket so that no cord leaves the device and in a way that the mains cannot be accessed unless done deliberately (e.g. someone cant poke something into a hole by accident and hit bare wire on the mains side)
basically fuse and isolation tansformer means you cant hurt the power grid, and there is a limit on the supply of how much power can be passed,
the socket and protection against stray pieces of metal means that you don't have to worry about all the BS of getting your cord certified and makes it so the only way an accident can occur is of someone deliberately tampered with it, (also the socket means your cord cant be chopped and is likely to be salvaged later on, keeping it alive
)
if the case is metal, tie it to mains earth, and being a power supply bring earth to another binding post on the front, and tie your internal earth to mains with a 1M resistor or higher, this covers all sorts of BS about charge equalisation of floating supplies,
as for the internals, the same old basics, make sure if there is something able to produce lethal or hazardous voltages make it so they cant be accidental bumped, or have a stray piece of copper come through a vent and short them out to external parts, and making sure there is some limit of current so you cant have it start fires with shorts,
and as a final note, if the heatsink is going to get F'ing hot, put a warning label or something near it, or a shroud to stop people touching it by accident, e.g trying to unplug it after hard use,