What is natural? Drs. Rosenfeld and rosato are right. If by natural you mean things that don't involve a medical procedure, none of them work. Don't waste your time and money. If you want to do something that is actually effective, you should have sclerotherapy on the legs or consider laser for the face.
There are none. "spider" veins are dilated blood vessels. Once present there is no "natural" way to eliminate them. Of course they may be covered with makeup.