NEVER EVER store your Louis Vuitton near moth repellant (beads, crystals, envelopes, cakes, whatever).  It causes the monogram canvas to wear prematurely, resulting cracks.

Unbuckle straps, as hardware leaves dents and stains.  This means you shouldn't hang it.

Stuff the purse with soft breathy material, such as old T shirts.  The monogram canvas is durable, but once it gets creases, it'll take a while to get rid of them.  Unnecessary pressure by folding for a long period of time could cause cracks on the canvas or the varnish of older pieces, too.  You want to maintain the shape of the purse while being stored.

Store in "some" cloth bags.  The typical felt bag that comes with Louis Vuitton is sufficient, but in some climates that get hot & humid (like Japan), I feel you'll be better off using something like a pillow case.  The Louis Vuitton felt bag is fuzzier and woven more densely than a thin pillow case.  All you want to do is avoid dust, so a cheap pillow case (definitely not nice 220-count cotton) should do the job.  Vernis in particular should be stored in the felt bag that comes with the item (or something very soft)!  Vernis is very very sensitive, and its color fades and transfers easily.  

It all depends on the climate you live in, but you should air your purses at least once a year.  You definitely do not want them to smell; a mildew (musty) smell would be very difficult to get rid of.

Monogram canvas is VINYL.  So you need not be TOO gentle with it, but it loses its sheen appearance.  This is mainly because dust & dirt accumulates on the surface since it's bumpy.  Use a mild soap (not detergent) with a sponge and wipe with damp soft cloth.  Do not rub hard.  The monogram canvas is a print, so you could make it fade by scrubbing.  If something is stuck (like food) in the bumps, just wet that area and let the stain absorb water so that you don't have to scrub.  Be extra careful with the leather parts when washing the monogram canvas!  You do not want water stains on your leather, so do not get the leather wet.

Gentle washing is all you need to do, but if you want extra shine, I use mink oil spray.  It smells rather strong, but the smell goes away completely in a few days, and it also does not harm the leather.   Armor All is controversial, although it's formulated to take care of vinyl & plastic.  Armor All does a wonderful job, but as per my husband (a car collector, "junk" cars, I might add), unless you continuously use it, some believe it causes dryness and cracks.  As old car's dash cracks after being exposed to the sun for many years, the monogram canvas cracks by years of use and being exposed to harsh weather. 

Monogram canvas does get thin after many years of use!  The print fades and becomes dull, but there's nothing you can do about it.  Time to hit the Louis Vuitton boutique!

Everybody who purchases a new Louis Vuitton purse with natural leather (most monogram models) gets very very nervous about the leather parts, or gets real surprised if it's their very first Louis Vuitton, because the leather is so sensitive to water and other staining.  Louis Vuitton leather is TOP QUALITY, but it's not dyed or coated.  It is very sensitive, and ONE drop of rain leaves a light water stain.  It'll tan over the years to its very famous "Louis Vuitton patina".  I'll explain this patina business in the "patina???" page. 

Leather needs to breathe.  So whatever you do, do NOT store in a plastic blanket case or a plastic tub and the like. 

Leather needs to be nourished; it will dry up and crack without care.  Again, depending on the climate you live in (big difference between CA and AZ), you need to use some kind of leather conditioner/lotion once or twice a year.  I'd advise against using anything in the first year (maybe two years), however.  If you use your new purse heavily (daily), I personally like the first year to be the natural "breaking-in" period.  I have no good explanation to this, so it's just how I feel.  We don't use a hand cream on a baby's hand (who doesn't do dishes!) unless there's an absolutely positively good reason to do so.  I believe it (baby skin or Vuitton leather) needs to be exposed to the air (and all the junk in the air), moisture, and oil & dirt from hands and other "stuff" in the environment in order to age naturally. 

As far as what to use, I recommend "Leather Care" conditioner by Apple Polishes, although it does stain (makes it darker) young leather somewhat.  It can be obtained at Burlington Coat if you have their store in town.  Check their web site to find out where to get one.  http://www.applepolishes.com/applepolishes/dealers/default.asp

Coach leather conditioner is also known to do a wonderful job.

What's NO NO is mink oil cream.  It contains animal fat that clogs the pores of the leather that need to breathe.  It is seriously greasy, so it stains the leather big time.  If you have Japanese catalogs & magazines (Perfect such & such) and happen to read the "care" section, many recommend mink oil cream to be applied thinly.  WRONG!  Believe me, you do NOT want to use mink oil cream.*
Mink oil spray on the other hand, does not stain the leather and it is a fine mist, so that it can be sprayed a little bit on the leather.  I don't think this much (or little) mink oil should harm the leather at all.  But for thorough conditioning, I recommend a lotion type, without animal fat.  Don't forget to condition the strap!