When you cannot use a bean bag you use a tripod. When you cannot use a tripod you use a monopod. When you cannot use a monopod, pray.
Just as with a camera: Get the best tripod you can. Get the best monopod you can. By best I mean: the best to shoot, the best to pack, the best to carry. Maximizing all three needs means paying for it.
A bad tripod is useless A monopod that flexes is mostly useless.
You may want to check this article on the subject of monopods