You really should use relays for each switch. If it were mine, I would do like the guy above and use main switch feeding the rest of the switches. Then from each individual switch, you need a relay. The 12v from the switch feeds the 85 post. Ground 86. 12v from the battery to the 30 post. And the 87 post goes to the lights that you want that switch to control. That way the only amperage getting pulled through the switches is for activating the coil on the relays. Very minimal. Not going to creat any heat. I'll draw you up a generic diagram in a sec.
85 and 86 just activate the coil, its doesnt matter which one is pos or neg. make sure that the wire going from the battery to the 30 post can handle the amperage draw from the lights. same with the wire from 87 to the lights. the wires between the switches and the relays, and the grounds for the relays dont have to be super beefy. 16 gauge will work for those.