Big 3 Part 1: Wires
Part 1 is to uprate the cabling thats often forgotten. It involves replacing a few factory cables (3!!) with something more substantial.
Wire 1: The ground wire between the battery and the car chassis. Replace this with at least a 4awg gauge cable.
Wire 2: Change the charging wire between the battery and the alternator. Again with at least a 4awg cable.
Wire 3: (Only applicable if your car has one!) Replace the alternator chassis ground cable with 4awg cable.