I use ankle weights:
https://www.amazon.com/ankle-weights/s?k=ankle+weightsAvailable cheaply (well, when there are no pandemic shortages) in 1-15lbs pretty much everywhere that sells fitness equipment in any color you want.
Velcro straps make it easy to wrap around tripod/stand legs as you would wrap around an ankle. Won't fall off and won't scratch your gear.
I also sometimes add a Manfrotto 035 mafer clamp to the stand (low) and hang a Nalgene from it. I have hooks that snap into the 035 clamps to make this easier, but it works without too.