exposing for the highlights
yes, that was my mistake this time round. I metered with the emphasis on the darker parts of the scene instead of the lighter parts. Anything with plenty of sky in it was blown completely, but scenes in more subdued light came out a little dark in my opinion. Next time I'll give the brighter parts more emphasis in metering and give a bit more exposure in the shady shots.
Still, it seems to be easier for me to interpret my exposure errors properly with a direct positive than it is with a B&W negative.