Now that you have some ideas for packing without wrinkles, how do you keep your things safe en route? I try to avoid checking bags whenever possible, but sometimes checked luggage is inevitable. Here are some tips to help:
Keep 'em dry
This is an easy one - if you are packing liquids inside your luggage (sunscreen, cosmetics, cologne, whatever...) put them inside a sealed plastic bag to keep them from leaking on your clothes. Don't leave a bunch of extra air in the bags, or they could pop open when your plane reaches a high altitude.
Lock it up
When you check luggage in the US, they require that your bags be unlocked these days - which makes me uncomfortable. There is another way - you can use a "TSA Approved" lock, which allow you to lock your bag but still allows the Transportation Safety Administration to gain access to your bags, since a TSA Approved lock has a special keying mechanism that allows TSA officials to open them. My favorite ones are the locks with a search indicator on them. I picked up a few of these at Target and use them all the time - they have a little dot on them that is green when you lock it, but turns red if your back has been searched. You have to know the combination to reset the dot to green, so it enables you to know when they've searched your bag.
They help in a couple of ways: 1) they prevent casual intrusion into your luggage, and 2) they keep your bags from accidentally coming open if your zipper gets snagged on something.
Know what you have
I've had lots of luggage delays, in which I make a connection and my luggage arrives on a later flight, or other such situations. But what if your luggage is truly lost? How do you know what's gone?
Thankfully, I've only had luggage go missing a couple of times, but it does happen. When it does, you'll be well served to have a list of what's in your bag so you can file a claim if it disappears. A simple list on an index card is sufficient, or you can go into more detail -- even taking a picture of the suitcase before you close it up, if you like.
If you must pack anything of significant value, be careful, pack the items well, lock your bag -- and consider alternatives. For example, you may be better off shipping your items to your destination via an insurable shipping method. This will help protect your precious possessions from damage or loss (and the claims process via the airlines is time-consuming and fraught with technicalities designed to keep them from paying you for anything).
Side note: Once, I lost my bag and didn't get it back for 6 days. I was told by one of the baggage claims folks that your odds of finding your luggage decrease significantly after a few days, because the bag numbers get recycled in their systems. For example, on United (the losemakers in that case), they purportedly go through 1 million bags about every 72 hours, after which your bag number is then assigned to someone else's bag.
Be wary of Chicago
I've only had a few luggage losses or significant delays. All of them have involved Chicago O'Hare Airport. I now avoid connecting through Chicago whenever I can, particularly if I have to check luggage. Also, I've experienced a statistically high number of weather delays and missed connections in Chicago.
Incidentally, Chicago is where my bag went missing for 6 days (it got "scanned" coming off the plane in Chicago but never made it to Montreal where I was going). When I got my bag back, several hundred dollars worth of stuff was missing including some trousers from a suit (I still have the jacket), an electric shaver, some new shoes, and some cologne. I had a list of contents and some photos and eventually got a claim paid for the items, but it was not a fun experience.
More to come
I'll have more in the future, including tips to reduce the number of things you pack to increase your chances of being able to use carry-on luggage instead of checking it.