I think the only way to prevent magin call is to minimize your trading lots size, remember that greedy is one of the reason we do have magin call, if we can trade with little lots size it's very hard we get magin call. With good planning it's hard we get margin call, use little lots for eevery trade it will help you not to have margin, don't jump into trade without proper analysis it will also prevent you fromfrom getting margin call