I use frozen berries two ways,

first, I just eat them frozen.  Actually I put them in a bowl and
run hot water over them for about 10 seconds so they arn't
super cold.  Then I often sprinkle a little brown sugar,
(yes I know it's not entirely paleo, but I don't use much.)
I especialy like blueberries, and there are frozen mixed berries
with blueberries, raspberries, strawberries.  Of course,
when the berries are in their native season and cheap
then I buy them fresh.

second my son likes to make smoothies from them.
berries, water, a little raw sugar, banana, maybe apple
chunks.  I've tried some of it.  It's good.

R. Keene