1. Overheating at slow engine speeds, at stop signs and with the A/C on at stops usually indicates a bad electric cooling fan motor up near the radiator.
2. Overheating at freeway speeds only, or at fast speeds but not at slow speeds usually points to a restriction in the radiator and a new radiator is the answer.
3. Overheating all the time, most likely a coolant leak and there is not enough coolant in the radiator

I always start with a cooling system pressure test first to determine if there is a leak, either internal to the engine like a head gasket or an external leak like a hose or water pump etc.