Placing the tank on a level, even surface is the only safe way to go. When I made my stand I used some type of cork-like tape(corkboard on one side, tape on the other). I secured the cork/foam to the top of the stand where the tank would rest on it. This ensures that the weight of the tank is spread evenly over the surface of the stand.
I wouldn't risk it with a shoddy stand, its a lot of work cleaning gravel out of your carpet!