I always do a basil pesto (without the cheese) to freeze in ice cube trays. I then transfer to freezer bags for winter storage. I add the Parmesan after defrosting. It just doesn't freeze well.
The cubes are the perfect size for dropping in minestrone or flavoring a tomato pasta sauce.
I also freeze small glass jars of pesto with more olive oil floating on top--enough pesto for a pound of pasta. These jars keep better than the cubes, but you have to use the whole bit at once.
I coarsely chop/puree Thai basil in the food processor and freeze in ice cube trays topped off with a bit of water to protect from freezer burn. Then store in freezer bags the same way as pesto. I was planning to do the same with oregano and cilantro this year.
Rosemary and sage, in our climate, are pretty much always on tap.
So I thought I had the preserving herbs thing down--without resorting to drying.
But this blew my mind.