MTG Salvation

In order to simplify the deckbuilding process, instead of deciding on 100 individual cards from the pool, instead all the cards are configured into groups (packages) of 9 (or maybe 11) cards with a common element (and color(s), for simplicity's sake). For instance, the package "GW lands" might have:
savannah
windswept heath
gavony township
grove of the guardian
horizon canopy
razorverge thicket
selesnya sanctuary
sunpetal grove
temple garden

The cards are separated into their packages within your deck box(es), and each card in the package has a sticker on the front of the card that identifies it as being from that package, with an additional number on it that won't matter until later. Packages could be very specific, as above, or could be a little more vague, like "black auto-includes", which might include tutors, like demonic tutor as well as removal, like decree of pain, or those might be in separate packages related to their function.

Needless to say, all cards have to be in the same sleeves.

In order to build a deck, pick your general and then pick 11 (or maybe 9) packages that work well with your general and fit within their color(s). Pull them out, shuffle up, and play. To disassemble, separate the cards by their stickers and put them back into their respective locations in the box.

If you have a specific, tuned deck you want to play, though, it's a bit more complex...you'll need a list of the cards in the list, by package with the additional number on them as well. Then pull out each package and remove the cards you need for the deck. Of course, you could try to configure the packages to match some of the decks you have, though, so you can use as many complete packages as possible.

To cube draft EDH decks, it's simple enough, except that you'd need to put everything back into the correct package when you're done. Better get your friends to help.

Plusses:
-ideal for making new decks given a relatively simple starting point
-not too complicated
-fairly easy to update
-even if you tune on the fly you can put stuff back where it goes when you're done
Minuses:
-slow to assemble existing decks
-can't have complete customization without more hassle
-can't include rare synergies (i.e. baubles with glissa, rebels with lin sivvi) without special, one-general-only packages, which is even less practical with, for example, wort, boggart auntie.

Ok, so bear with me.

Step 1: get a list of EDH decks.
Step 2: combine the lists and remove the duplicates, so you have one long list
Step 3: get 1000 or so toploaders.
Step 4: drill a hole in the bottom of all of the toploaders.
Step 5: glue all your toploaders together into one giant perfectly-straight stack, you crazy bastard.
Step 6: put all your cards into the slots in your crazy toploader stack in some order you've written down (might want to number them for easier replacement)
Step 7: for each decklist, make a sort of....weird, comb-lookin' thing. like, a long piece of something with a bunch of little pokey-things sticking off of it. And make sure all the pokey-things are lined up to exactly where the cards in the deck are.
Step 8: to retrieve a deck, stick the comb into the holes in the toploaders and push out the cards. Or, probably not, probably the cards will get stuck in there and the pokey-things will slide over or under them. But, I mean, hopefully they come out.
Step 9: play your deck.
Step 10: put them all back into the corresponding slots, and you can get another comb for your other deck and play it instead.

Plusses:
-in magic christmas land, it's an easy way to configure a slew of existing decklists
Minuses:
-in reality, the stack of toploaders would be huge, the "combs" would never line up, they'd never push all the cards out, it'd probably take up more room than having dozens of regular decks with you, the combs would be really fragile and awkward to carry, and you'd probably damage the cards.