measuring capacitors
If you know the nominal capacitance, and you have just a multimeter and some resistors, then you can measure (within perhaps 10%), but you will need a separate voltage source with known voltage.

Choose a resistor such that C (your capacitance) times the resistor is about 5 seconds. The time to charge the capacitor to 63% is R * C.

Connect the resistor and capacitor in series and connect the multimeter across the capacitor in volts mode. When you are all set, connect the external power source (be careful not to exceed the rating of your capacitor).

The voltage across the capacitor will rise, and take a measurement at 63% (at whatever R * C came out to) of the external voltage source recording the time taken.

The capacitor has a value of time (recorded) / R, as this time is equal to nominal R * C.

Good if you have limited tools and need a rough and ready measurement.