You can't. When you get a quote for car insurance the premuim will be worked out to that company's own underwriting criteria and they don't make this public. This (commercially sensitive) criteria will work out a rate based on, quite simply, how badly they want your business.
If you are considered a good risk the Gross Premium will take into account various deductions if you are:
1) someone who has a clean driving history (eg: no accidents or claims or convictions on your licence).
2) Your vehicle is a modest family car.
3) You use it just for commuting and social & domestic.
4) You and no one else on your policy is under 25.
Each of these will be worth deductions of 10%, 20% etc...
However some of the information you will have given might cause the insurance company to raise (load) the Gross Premium.
1) Your vehicle has non-spec modifications on it for example.
2) Or you may live in an area that has a high incidence of car theft.
3) You don't have a garage and the car is parked at the side of the road overnight.
But certainly if you live in the UK the days of cheap car insurance are over. If you want to keep your premium down to a minimum make sure that: you are average, your car is average and you will only use it an average amount.