Get an international driver's license if you plan to drive a car in a foreign country. You will need a license to rent a car.
Check your existing car insurance policy for the coverage if you are a frequent flyer to other countries. Ask your insurance company if they can include exactly what you want in your existing policy. This is one of the best ways to get insured.
Choose the option of getting insurance from the rental company if you do not have the requisite coverage in your existing auto policy.
Check your credit cards and memberships. Some cards like American Express and MasterCard cover you for auto insurance when you are traveling abroad and driving a rented vehicle you charged on your credit card.