There are several types of insurance you may consider in addition to the mandatory professional liability insurance. For example, consider that something might happen to you personally (as opposed to your premises or property). You may wish to consider investing in life insurance to help pay for the winding up or sale of your practice. Also consider what would happen if you were injured while on vacation, for example, and were not able to work for a long period.  You may wish to consider disability insurance in the event you are unable to work, or need to pay someone to carry on your practice during a disability.
Also consider whether you need property insurance for business premises, business interruption, general commercial liability insurance for injury to people or property, and insurance for the contents of your premises (including such matters as riders for things like laptops, etc.).

Where to Start?

You should start by taking stock of your entire inventory. In turning your mind to the issue of insurance, you will have to consider the coverage options that are best for you. This is an ongoing process. It is useful to review your insurance coverage at regular intervals, as you review your plans for continuity and disaster.
You may want to consult a knowledgeable commercial insurance broker to find out more about the types of insurance available.  In addition to obtaining insurance, something as simple as arranging a line of credit can assist you if disaster strikes and disrupts your normal billing cycle. It may take longer than anticipated to get your practice back up to speed, if for instance the building where your office is located is severely damaged by flooding, and the insurer is not able to process your claim immediately. You may need cash faster than anticipated. A line of credit will help.