500ml of your favourite fizzy drink
Zip lock bag (big enough to hold 500ml)
A big zip lock bag that the other one will fit into
1 Tbsp rock salt
3 Cups ice
A glass
A straw

Pour drink into the small zip lock bag.
Put the rock salt and ice into the big bag.
Seal the small bag tight and put it into the big bag and seal the big bag tight.
Shake for a good 8-10 minutes.
Once it seems ready, take small bag out and pour the drink into a glass. Enjoy!

Tip: don't use to much fizzy drink it might pop the bag. Don't ever freeze a drink it makes it lose it's taste. I have never tried juice but it probably will work well.