Securing your home is the best way to reduce your chances of being burgled. A lot of burglaries are spur of the moment and committed by opportunist thieves who see an open window or other easy point of entry. Nationally 37% of burglaries occur in properties where either windows or doors were unlocked, so taking the simplest of measures can reduce your chances of becoming a victim by over a third.
Spending money on security measures can seem daunting but it is a good investment and can add value to your property. If you rent your property your landlord has some responsibility towards its security, therefore if it not currently secure, ask your landlord if they will make necessary improvements. If you live in social housing or in a block of rented flats, forming a tenants association might make security easier.
Make sure that any improvements you make don't stop you from getting out of your house as quickly as possible if there is a fire.