If you have a bench power supply with a current control its easy to measure small
resistances in combination with a multimeter:
Set the PSU to 1A limit, connect to the resistor under test (it is a small resistor so I-squared-R
will be small and thus won't fry).
Measure the voltage directly across the resistor right on the terminals (not along the wires),
this forms a 4-wire Kelvin measuring setup.
Since the current is known to be 1A, the resistance in milliohms = the voltage in millivolts,
easy!
You can separately calibrate the current setting on your PSU using the amps range on
the multimeter if you want to check its accuracy.
Remember just ordinary bits of wire lying around will have resistances of from a
few milliohms (thick cables) to 100's of milliohms (small signal wires). Oxidation on
plug and sockets can add tens to hundreds of milliohms too...