You are facing a classic chicken and egg problem. You want premium projects but cannot get them because you haven't done any yet. To solve this, you need to think from your target customers standpoint. Why would a customer buy from you? What do you offer that others don't have? Once you define that, the second thing you need to understand is how companies acquire their services. The buying process in a company is different from consumer buying cycle. So you need to figure out how you will play this dance.
Lastly, to acquire customers, you will need to do some marketing and network. LinkedIn would be a good starting point.

Another option would be to start out small and bid for projects on oDesk, Guru or other similar sites
All the best.... Happy to talk if you have more questions.