[noun] + でも + [noun] + でも [na-adj] + でも + [na-adj] + でも
AでもBでも means "whether A or B": the same holds for both, so the choice doesn't matter. でも goes straight after each noun or な-adjective.
A verb or an い-adjective uses its own て-form with も instead: いって行ってもいかなくて行かなくても, たかくて高くてもやすくて安くても.
These go beyond two items and an affirmative.
When the sentence ends in a negative, it is true of neither: "not by A or by B".
A word like なん何でも, いつでも or どちらでも after the list says the items were only examples.