Large loss: The size of the loss must be meaningful from the perspective of the insured. Insurance premiums need to cover both the expected cost of losses, plus the cost of issuing and administering the policy, adjusting losses, and supplying the capital needed to reasonably assure that the insurer will be able to pay claims. For small losses, these latter costs may be several times the size of the expected cost of losses. There is hardly any point in paying such costs unless the protection offered has real value to a buyer.
Accidental loss: The event that constitutes the trigger of a claim should be fortuitous, or at least outside the control of the beneficiary of the insurance. The loss should be pure, in the sense that it results from an event for which there is only the opportunity for cost. Events that contain speculative elements such as ordinary business risks or even purchasing a lottery ticket are generally not considered insurable.
There are also companies known as "insurance consultants". Like a mortgage broker, these companies are paid a fee by the customer to shop around for the best insurance policy amongst many companies. Similar to an insurance consultant, an 'insurance broker' also shops around for the best insurance policy amongst many companies. However, with insurance brokers, the fee is usually paid in the form of commission from the insurer that is selected rather than directly from the client.
Cash in on major life changes. Certain life events could translate to cheaper car insurance, so shop for quotes whenever something major changes in your life. For instance, many companies offer a lower rate for married couples or domestic partners. Or perhaps you moved to a suburb with lower accident and crime rates. If your risk for accidents goes down, your rates just might, too.