Hi All,
I hope you never need them but if you do you need them in a hurry and usually have to make them yourself. I have made hundreds of sandbags and seen many crazy ideas on how to make them. What works best for me is to cut the inside out of the bottom of a plastic five gallon bucket. Put the bucket in the bag and set on the ground and fill the bucket 1/2 to 3/4 full. pull the bucket from the bag. Repeat as necessary.
Enjoy, Chris