When I bought my first really nice handbag, I babied it for weeks. Every little drop of water was cause for panic. Eventually, I remembered my grandmother's words and my gingerness passed. But I've also learned some secrets for keeping leather bags looking nice, if not new (and personally, I think most bags look better once they've been a bit broken in).
To help make leather more water and stain resistant, many people swear by Apple Garde. I've used this spray on untreated vachetta leather, on Balenciaga leather and on suede, and have been quite satisfied with the results. Don't panic if the leather darkens when you first apply; give it an hour or so and once the leather dries it will return to it's original color. Test it on a small corner or area that doesn't show if you're hesitatant. Apply two coats, and reapply every six months or so. If the leather is dry, use the Apple Leather Care conditioner first.
Thanks to the ever-knowlegeable ladies at The Purse Forum, I've discovered Lovin My Bags leather care products. Pro-Treatment is a cream that protects against water AND oil stains, and I've begun using on all of my non-metallic bags. For Handles Only protects those vachetta, Balenciaga and other light colored handles from turning dark as a result of absorption of skin oils. Shine Restore will put that gleam back in the leather, and they even have "Odor Out Candies" to make your bags smell sweet again (a must for those who buy on ebay!). There are special Vintage and Balenciaga care kits, which IMO would make a nice holiday gift for a bag lover, and various cleansers.
Barbara at Lovin My Bags also offers restoration services and has done extensive research on how various leathers are made and dyed, and how best to preserve and restore them. If you want to see some absolutely amazing pics of handbags brought back from the brink, go visit her blog.
One thing I've also learned from reading her blog is to NEVER use saddle soap on handbags. The soap is alkaline and actually breaks down the leather (one of the reasons it's so effective at softening stiff saddle leather).
A gadget I employ regularly to help preserve my favorite bags is a Purse Hook. No more having to set your bags on the dirty floor (gah!) or hanging them over the back of your chair, and risking that they end up on the floor anyway. It braces on the top of a table, and the weight of the bag keeps it in place. Your bag is out of the way under the table, and conveniently in reach. I keep my Purse Hook with me in whatever bag I'm carrying.Purse Hook ... Purse Hooker ?
Grand-mere was right. Protect and then use your beautiful bags!