How did the roman worship their gods?

The way the Romans worshiped a god, depended upon the god. Some, had elaborate rituals that had to be performed, others were content with just a parade of the statue or image. Most gods needed a sacrifice of some type, for example, a harvest god, was offered the first fruits of the harvest, in order to insure the gods help in granting a good harvest the next year and a triumphing general would always offer up part of his spoils to Jupiter. However, many forms of worship were in Thanksgiving or in fulfillment of a vow. Altars and shrines were erected for these purposes.