Hi Billy,
Freezing is good, it breaks up the cell structure and gives better juice extraction :thumb:
I will be picking a pound or so of blackberries every day to my way to or from w**k and they all get washed and frozen until I've got enough.
Rosehips go a long way, it only needs 2lbs to the gallon for wine, but that's a helluva lot of the little blighters. The cultivated kind are available first, I cut those off as close to the stalk as I can then twist off the fluffy bit with my thumb nail, wash and freeze.
The cultivated ones are quite soft and prone to insect attack, Look for puncure marks. When you've twisted the top off, look inside every one, if they are a bit grey, split them and look for tiny maggots. You will soon get to recognise the danger signs.
The wild ones come on much later, and should ideally be picked after the first frosts. These are much tougher and insect resistant. I snip the tip off with kitchen scissors and split them before freezing.
You can make a syrup if you like, google for the method, but I've never bothered.