One of the most common mistakes made by business owners is targeting the wrong keywords. You need to think what your customers would type into Google to search for your business.
For example Estate Agents always seem to want to be top for keywords like “estate agent london” however the better keyprhase would be “houses for sale london”. More people are looking for a house for sale so the traffic is higher and also do they really care which agent is selling the house or do they care what house is on the agents books. You can use various tools to find out what people actually search for online my favourite is Googles keyword tool which you can find here.
Please note this tool will constantly change as Google is always updating it.