It matters whether I'm sorting a deck, or my collection.
First, separate into the following sets:
White
Blue
Black
Red
Green
Multicolor (Including
hybrid multicolor
)
Hybrid
Colorless Nonland Artifacts
Other Colorless Nonlands
Land
For W/U/B/R/G, creatures and noncreatures are separated from each other. Then, for each, the cards are sorted by mana cost (
not converted mana cost:


comes before


.) and finally alphabetically within exact mana cost.
ODDITIES:
Costless colored cards come first, then 0-cost colored cards (like pacts). monocolored cards with variable costs are fixed at their highest possible value, so
Beseech the Queen
is 6-cost with 3 symbols, and all X spells go at the end: Each X is treated as though it equals 1 billion. if they existed, Y would be 1 google and Z 1 googleplex. Functionally, this means that


comes before



comes before



would come before



, ALL after any black card of the same category with no X in its mana cost. Different printings of
Drain Life
and
Fireball
have given me headaches.
Multicolor is separated into creature and noncreature, THEN by exact color combination. First allied color pairs clockwise around the wheel from blue/white, then enemy color pairs in the same fashion (First color, second color: b/w, w/r, u/r, u/g, b/g). Following that is allied tricolor clockwise around the wheel by central color starting with white, then "Wedge" enemy tricolor around the wheel clockwise by shared enemy starting with white. The nephilim come next. they're unique right now, but if they ever become not unique the sort for 4-color cards will be lowest color value to highest (color value assumes White = 1, blue = 2, and so on to green = 5, so the nephilim missing green comes first, followed by the one missing red, counterclockwise around the wheel until you get the one missing white). Finally, 5 color comes last.
Each color combination is then sorted by CMC, then by number of symbols, then alphabetically. Becasue of the multicolor hybrid cards mucking things up, I don't care about what colored A card that costs



and one that costs



are just alphabitized against each other. (So Giant Ambush Beetle is multicolored creature tricilor

-centric allied, 5 cost, 2 symbols, 'G')
Hybrid is done exactly the same as multicolor, except it only has to worry about enemy and ally color pairs, not the more complicated, late-run sorts.
Each pile of colorless nonland (artifact or otherwise) is sorted in the same manner as colored cards, except for the part where color weight would matter.
Lands are sorted into basic and nonbasic. Basics are put in color-wheel order, nonbasics just alphabitized, because I don't like
Dryad Arbor
enough to set it entirely apart.
This is all the same whether I'm sorting a deck or a collection, but how the piles are compiled is NOT.
If I'm sorting a deck, the order is Basics - Nonbasics - Monocolored creatures in color order - multicolored creatures - hybrid creatures - colorless artifact creatures - colorless nonartifact creatures - monocolored spells - multicolored spells - hybrid spells - colorless noncreature artifacts - colorless nonartifact noncreature spells.
If I'm sorting my collection, the order is White creatures, white spells, blue creatures, blue spells, and so on through the monocolors, multicolors, hybrids, colorless artifacts, and nonartifact colorless, with land at the end. This is largley because each of the primary colors has its own box.
I realize typing it out that this sounds REALLY, REALLY COMPLICATED. However, it's not --
Magic is complicated and involves a lot of exceptions that I have to account for in my system. The simple way of putting it is the following sorts, rougher to finer: Exact Color, Creatureness, CMC, Chroma (number of colored mana symbols), Alphabet.
If you must know, my system grew out of the decklists and starting arrangements of old, Tempest/Urza's Saga era precons, which is why I do funky things like setting

to "Very large" rather than to 0 as it should be: the X spells in those precons were always listed at the end.