The addition of an extra couple of washers/nuts to the headset press, in order to hold one of the press-plates perpendicular to the rod, make it a much, much better tool.
For crown races, I just Dremel a slot in them so the they require very little pressure fit/remove. This obviously only applies to headsets with sealed cartridge bearings.
An adjustable spanner is perfect for trueing discs.
Not a tool as such, but heat-shrink tube instead of crimp-on cable-ends.