There are few things which you should follow if you are going to register a domain name.

You should always register domain name from top providers like Godaddy so that your domain name would be secure and you can do any serious business with your domain name.

You should try to use short domain name if possible.
Your domain name should use main keyword or company name if possible.
Try to register domain name on top extensions like .com, .net, .org etc.