For a domestic flight, the reimbursement limit for checked luggage is $2,500 per passenger, says Anolik. For international flights, it's $9.07 per pound.
Each airline will also have its own policies on what it will and will not cover. (Check the airline's Web site for the fine print.) You can usually rule out things like electronics, prescriptions and jewelry, he says.
And don't forget to include the expenses you incurred when the bag was lost, says Anolik. How many hours did you spend on the cell phone talking to the lost baggage office? What did you have to buy to replace your items so that you could continue on with your trip? What costs have you amassed in filing a claim?
If you lost such high-ticket items as electronics or jewelry, consider tapping your home insurance policy to replace it. If it's below the deductible or not worth the risk of escalating your premiums, chalk it up to an expensive experience and move on.
It's also worth checking with your credit card company to see if it covers any of your losses, says Foster.
When it comes to covered goods (mainly clothing), the airline will not be buying you anything new. Airlines most often replace your goods at depreciated value. (Think garage sale, not shopping spree.) Instead of buying you a new suit to replace the 3-year-old one that they lost, they'll likely give you the value of that new suit after three years.
It may help if you have the original receipt for the suit. If you don't (and who does?), you might be able to get a copy of your credit card bill from your card company or a picture of yourself wearing it at that last anniversary dinner.
And hold out for the true value of your goods. If the airline is trying to pay down-market prices for up-market clothes, set them straight. Look to people familiar with the quality of your clothes, such as a tailor, dry cleaner or the manager of the clothing store you frequent, to give you a note to help document your claim.
Just like other areas of life, there is "plenty of room" for negotiation, says Stempler.
"Don't have great high hopes and be extremely patient," says Foster. "It may take six months."
Best overall advice: Stay calm and cut a bargain you can accept. If that doesn't get you a fair settlement for what you've lost, try small claims court, says Anolik.
If you're dealing with lost luggage, the main thing is not to let the situation get to you, he says. "Relax, go on with life and don't aggravate yourself," says Anolik. "You can take care of it when you get home."