John K Jordan
FWIW, I try to dry slowly (mostly air drying) but regardless of the method I monitor with weight. Microwaving small pieces, I try short times and feel the piece to make sure it gets warm and not hot. Let cool, weigh, repeat. When weight quits decreasing, it's dry. Microwave drying can make the wood much drier than equilibrium for the environment so I take that in consideration and let it sit for a while if movement might be an issue as it takes up moisture from the air.
For air drying (mostly woodturning blanks), seal, then weigh and record, set it on the shelf for some time (usually a month or more), then repeat. When the weight no longer decreases (or even goes up with the season), it's air dried.