Use an RLC bridge. If you don't have one, then connect to a capacitor of known value and see what frequency it resonates at.
The best way to measure is to install it where it will be used before doing any measuement since air coils can change value depending on the surrounding environment. Baffle shields, circuit boards, etc. can all act like a shorted out secondary, and that will reduce the inductance below what you'd measure away from any conductors.
For the most part, inductors don't have to be all that accurate. That's what trimmer capacitors are for.