So you are going on a trip and realize that you booked the wrong flight or you can't go now, because you lost your job or you have an important event to attend. Did you purchase trip insurance? You can salvage some of that money, even without trip insurance.
Trip Insurance. You should really only consider trip insurance if you are spending a lot of money on the plane tickets and you are in dange of an emergency, like having a sick family member. Most people don't realize that trip insurance does NOT mean you can cancel your trip for any reason. Read the fine print, most often it takes a severe situation to get your trip insurance money.
Cancelling a purchased flight. Most of the major carriers allow you to cancel a flight right up to it start time for a $150 fee. If you cancel within 24 hours of the purchase, you do not have to pay any fees. Sometimes that is not always possible, so you can cancel your flight. If you fly on charters or smaller airlines, the fees can be lower. Allegiant Air offer Trip Flex for $15 and you can change your ticket. Keep in mind that the $150 comes off the back end of your flight, meaning, you don't get refunded $150, you get a credit for the difference on a future flight on the same airline.
So the best way to get your credit is travel again on the same airline with a ticket that is about the same price. Any charges over the original price get tacked on to the new ticket.
One other item. Travel waivers are one other way of changing a ticket without penalty. This can happen in the event of area weather concerns, such as storms, flooding, fires and other natural disasters. When this is happening check the airlines website for the announcement and call and reschedule. This is a great to get out of flights, when you are not sure if you should travel.
You could also pay double the price of a regular ticket for the refundable option. This may be a slight exaggeration but most times, refundable tickets are quite a bit more - so you are best off making sure you trip is good to go barring a major emergency.