Firstly, shop around for your home insurance. With so many companies offering so many different deals, you may find big savings or a more appropriate level of cover at a cheaper price.
There are lots of price comparison websites, and most will help you understand the different levels of cover as well as just quoting prices. It is important that the policy you have meets your needs so do look at the details.
If you get your buildings and contents insurance from the same company you will often get a better price. Some insurers offer further discounts when you buy your travel and car insurance at the same time as your home insurance.
You can increase the voluntary excess on your policy to reduce the premium, but be realistic about what you would be able to pay. Remember the whole reason for having home insurance is to protect you financially if your house or belongings are damaged, so there is no point in getting a really cheap policy that would still leave you financially crippled if there was a house fire for example.
To further reduce your premium, fit an approved burglar alarm and get proper locks. This will also of course reduce the chances of a burglary which is not just expensive but can be very traumatic.
If you can afford to pay a one off sum annually rather than in monthly instalments, most insurers will give you a discount. Lastly, if there is one then make sure you join the local Neighbourhood Watch scheme, this is free and can reduce your home insurance premium.
In your attempts to reduce your premium, dont be tempted to lie to your insurer about the condition of your home because otherwise the insurer may not pay out.