You lose your luggage
Solution: If your baggage hasn't shown up on the conveyor belt - be patient then go to the airline's counter to file a report. They may offer you a bag of essentials (i.e. toiletries) and will take your contact details. Be aware that the longer your luggage is lost, the more compensation the airline will provide. Your travel insurance policy will probably cover lostinsurance policy will probably cover lost luggage too so check the wording on your policy. Be aware that if you lose your bag after you've left the baggage claim area, you need to contact the police, not the airline.
Top tips: Label your bag clearly and put something recognisable on it (i.e. a colourful ribbon around the handle) so nobody takes it by mistake. Also take a photo of your suitcase in case you need to show this to the airline. Keep all valuables (as well as medication and glasses/contact lenses) in your hand