Generally each year your car insurance premium will rise, to find cheaper car insurance we recommend shopping around when your car insurance premium is up to renewal.
Many companies offer cheap car insurance if you are over a certain age or in a particular class of driver. Women, for example, are often offered cheaper insurance than men. Some companies specialise completely in cheap insurance for women.
Drivers with a good driving record may find car insurance gets cheaper as they get older. Some companies refuse to insure younger drivers in high performance cars.
What you consider to be insignificant changes may have an impact on your car insurance premium. For example keeping the car in a garage overnight may result in cheap car insurance. The removal of speeding points or driving less than 12000 miles a year almost always results in the insurer offering you a cheaper premium. Conversely the addition of points on your license or driving more miles per year may well result in a higher premium being demanded.
The best advise we can give is to keep your insurance company up to date with all changes in your circumstances and always shop around when you premium is due for renewal.