There are several different types of home insurance policies, and each has a standard set-up that insurance companies follow. The most common policy type is known as an HO-3 and includes the following coverages: Dwelling, Other Structures, Personal Property, Loss of Use, Personal Liability and Medical Payments. Typically these policies are a hybrid of open peril and named peril coverages and include endorsements providing your policy with replacement cost rather than actual cash value.
Most companies do not allow you to adjust the limits for the core coverages as they are set percentages of the dwelling limit. There are some, however, that may offer slightly different options. For example, personal property is typically 70% of the dwelling limit, but you may have the option to set it at 60% instead.
There are also optional endorsements that companies offer such as water back-up, identity fraud, and valuable items. A licensed home insurance agent can help you decide if there are any you may need to include on your policy.