The weakest way to argue against a point is to simply state that it’s incorrect. The next-weakest is to state that it’s incorrect and supply an alternative. A bit better is to state that it’s incorrect, supply an alternative, and offer reasons in support of that alternative. Better still is to do all of the above and, in on top of that, explain why the original point was incorrect, e.g., by pointing out where it falls short, contradicts itself, leads to an absurdity, etc.
Most people stop here. But the only way to truly close the loop on an incorrect point is to also explain why one would have good reason to believe it in the first place, and to account for those reasons in another manner. Only then is the entire dynamic of falsehood accounted for.
Example: If I think that the sky gets its colour from the ocean, someone who disagreed could simply say “No.” Or they could say “No, the sky gets its colour from the sun.” Or they could say “No, the sky gets its colour from the sun because sunlight that hits the earth is scattered by all the gases and particles floating in the earth’s atmosphere, and blue light is scattered more than the other colours because it travels as shorter, smaller waves.” Or they could say “No, the sky gets its colour from the sun because… And in any case, the sky can’t get its colour from the ocean, because the ocean gets its colour from how it reflects and absorbs sunlight—the same light that has already passed through and “given colour” to the sky.”* Or finally, to close the loop and account for the false belief: “No, the sky gets its colour from the sun because… and it can’t get its colour from the ocean because… However, I could see why one might think that the ocean is the cause of the sky’s colour, given that both are blue, and that the gaseous nature of the sky makes it seem less like an “object” with its own colour than merely the reflective glow of another object, in this case the ocean. But the air is made of molecules too, of course, and the seeming coincidence that both sky and ocean are blue has to do with commonalities in the molecular makeup of each, etc.”
*: One could go very far here and add something like,“If the ocean were to be the cause of the sky’s blueness, that would mean that either the ocean produced it’s own light, or that the reflective power of blue light bouncing off the ocean’s surface is stronger than the sunlight hitting the atmosphere directly, or that sunlight somehow hits the ocean but doesn’t touch the sky, all of which are absurd or unlikely, etc.” or something of that sort.