Drying/Preseving Herbs

As it is that time of year when things will start to die back or get nipped by the frost, I need to get my finger out and work out what I am going to do to preserve the herbs that I have in the garden, and also what I need to do (if anything) about over wintering or to have things come back in the spring.

I have a dehydrator, a vacuum sealer and am no stranger to pickling - freezing isn't currently an option, as the freezer is full.

So, your advice please ladies and gents, on the following:

Parsley (flat leaf) - dehydrate/dry - sow fresh seed in spring

Thyme - I have this dried already, so no need for more, but does the plant overwinter?

Rosemary - same as thyme

Sage (purple) - how well does this dehydrate? Is it a sow fresh thing next year?

Lemon verbena - not a clue

Lemongrass - not a clue

Horseradish - not a clue

Mint - maybe dehydrate, but not sure. Assume it comes back next year.

Oregano - as per thyme/rosemary