I can't think of a useful sanction, except those requested by the people of South Africa. This is likely to head down the same track as Oil for Food, enriching a very few corrupt people on both sides and driving dissent so far underground as to no longer exist. Sanctions are a very blunt form of blackmail, just like a nuclear threat. The US used both on Cuba and nothing worked. And it is very doubtful that this will work. Haliburton, a major contractor in the oil arena will just build a refinery or two for them. They already do lots of work for Iran. And if it's not Haliburton, it will be one of the Texas or Oklahoma outfits that dealt with Saddam. Or maybe Exxon Mobil or Standard of Ohio.
53-year-old Israeli woman lightly wounded by stone-throwing near Efrat settlement (Haaretz)
from the article: U.S. warns Iran: Meet nuclear obligations or face 'next step'