Making sand bags is a very useful thing to do especially if you live on or near water, or in a low-lying area, where there is chance you could be flooded. You can make these bags and keep them ready to be filled with sand at a moment’s notice. Of course, you will need to have ready access to sand or gravel when the time comes to prevent damage of your property from flood waters.
Find a sack. The size of your sack will depend on how big you want your sandbag to end up. The best size would be about the size of an average pillowcase or a little bit smaller. However, if you do want one that's bigger or smaller, it's possible to make. Try not to make them too big or they will be too heavy to lift once they're full. Also, you want a sack that's strong.
Fill the sack with sand or earth. You can find sand or earth in a DIY store such as Home Depot or B&Q. You want to fill them so you can't fit in much more sand/earth but not so full that it will eventually burst or you can't carry the bag.
Secure the top of the bag. To secure the top of the bag, tie a very tight knot in the top of it using a piece of string. If the knot is too loose, it will come undone and your sandbag will not be any use to you. Test the knot by lightly tugging on it to see if it will come undone. If it does, tie it again. If it doesn't, your knot is fine.
Use the sandbag. Put it on the edge of your trench or in that gap that's been annoying you all year. Whatever the use is, your sandbag is sure to fulfill it.