An idea for starting a new business comes by observing the things around you, concentrating over the needs that could become an opportunity for you. As Andy Boynton says, the world around you is filled with ideas that can be useful.
Believe me ideas does not come to your mind by sitting on shore looking at the sunset or by thinking hard and having yourself in the vacuity. You cannot get an idea for new business by your smartness but you can hunt for an idea smartly.
There are couple of things which can help you in finding new ideas for the business happening around you:
List all the opportunities available to you. On a daily routine list down the jobs that have been ignored or not done by others efficiently. Look at the things around yourself as your own problems can drive you to a new business idea.
Creativity is the key to new ideas; usually such part of yours will reflect when you are relaxed such as on a visit to an art exhibition or may be on picnic with your family. Idea hunters even when talk to other people they try to dig out the ideas around them or listen to their unsatisfied experiences carefully to get a spark which they can make fire.
See the way others work out to resolve business issues. Noticing what others are doing can also help you in generating a new idea for your business. You may get inspiration from others idea and can tweak it accordingly to solve the problems you might have observed.