How Do You Handle Tantrums in Toddlers?

Billy and his wife have two boys a three year old and a nearly just and a just turned one year old. We're in no way experts on tantrums but we've done the hard yards with the three yearold and have learned a lot. When our one year old started throwing what seemed like full blown tantrums when he didn't get what he wanted we tried a lot of tactics and nothing has worked. This started from nine months old and his daycare educator in the trade for 20 years said that he is the youngest she's ever seen throw a proper tantrum. But my question is how do you handle tantrums in baby toddlers babies or toddlers this young? How is this starting