Start by avoiding connecting flights - direct flights reduce the chances bags will be lost.
Take pictures of your luggage, inside and out. If your bag is lost, it will help the airline track it down.
Use baggage tracking apps. Many airlines allow passengers to track their bags. You can track your bags yourself with a device like an Apple AirTag.
If your bag is lost, make sure to check the airline's claims policy.
If your bag is damaged, be sure to report it. Airlines are liable for damage to wheels, handles and straps. And you can always insure your bags for loss and damage.
If your bags do get lost, keep receipts for any expenses like swimsuits or toiletries. You could get reimbursed.