A few (3 or four) heaping cereal spoons of flour (I prefer white)
A pinch of salt and pepper
2 Cups of Macaroni Noodles (or more, if you want)
Butter, lots of it (I just use Smart Balance, it makes me feel better about the Trans Fat in the cheese and all the calories and carbohydrates and it smells AWESOME imo. Or just use regular butter.)
As much cheese as you can handle, I prefer sharp white cheddar (it tastes great and has the nicest golden-brown color when baked!)
Bread crumbs! (store-bought or made yourself)
You need two pans, one for the macaroni and one for the cheese sauce. The cheese sauce pan should be fairly small, and the macaroni pan should be large enough for all your noodles and about three or four times the noodles' height worth of water. Set the macaroni pan on high and put the lid on to get the water boiling quickly (and no, the macaroni does not go in until the water is boiling.) You can set that and forget it for a little while while you work on your sauce.
Put about half a tablespoon of butter in the bottom of the sauce pan and get it to melt, then pour in the 1/2 cup milk. Stir it briskly with a whisk for a little while to mix in the butter (kind of pointless, but I like to, anyway), and then add the flour. Now, this is very important- do this or your sauce will burn! Mix the sauce quickly with your trusty whisk. After a few minutes or so it should begin to become more like a gel (and becomes a bit thicker, harder to stir). At this point, add as much cheese as you want to the sauce and turn off the heat on the sauce pan. Mix it with a regular large spoon for a while and mash it all up, and then stir it heavily with your whisk until you can't see a single clump. If it is far too thick to move around in the pan on its own accord when you move the pan about, then you should slowly add more milk into the sauce until it's less viscous. This might take a little while, and if it isn't working well, heat it for about a minute (while mixing). Eventually, it should be a nice, consistent cheese sauce. Now, stir in a little salt and pepper for extra flavor. And add more butter. Butter makes everything taste good.
Back to the macaroni:
Once the macaroni pan reaches boiling point, remove the lid and pour in all your macaroni. You will now have to wait, stirring occasionally, until the noodles engorge a bit and fill up the extra water space. The macaroni brand I use usually takes 18-20 minutes to reach perfection, and this may vary based on your noodles. Do not leave the macaroni going too long or it will become floppy and gross, and it will turn into paste during the baking process.
Once the macaroni is ready, strain the macaroni, put a large clump of butter in the now-empty macaroni pan, pour back in the macaroni into the pan, stir it up with the butter, add most (BUT NOT ALL) of the cheese sauce (and maybe some more cheese for good taste). Now, pour all of your macaroni in to either a large bowel or a large, deep dish (depending on how much you've prepared). If you desire, at various depths sprinkle in more cheese to get a more thorough taste. If you only made a bowel or two, the next step can be easily done in a toaster oven. Otherwise, you're going to have to use your oven.
Pour the remaining cheese sauce over the bowel(s) or deep dish of macaroni, sprinkle it lightly with bread crumbs, and sprinkle on some more cheese. This makes the top sinfully delicious. Put in the oven or toaster oven on a light setting until the sprinkled cheese kind of melts and goldens and the bread crumbs do likewise. Take out with oven mitts or something, let it set somewhere for about five minutes (depending on how much you made), and dish it out or chow down.
/a tribute to macaroni, the most godly thing on earth.
I figured all of this out on my own by accident when I was making some cookies for Christmas a while back and developed it from there. Results may vary