I suppose the first question to ask yourself is why would you want to? If this is a career goal then there are a couple of solid strategies to put in place early.
1. Make certain that you build a strong reference list during your time as an independent. This will be invaluable when you start to interview in the consulting firms. They like to see that you have built a solid portfolio of contacts which may be useful to them in the future.
2. If you are working with known products or solutions make sure that you are also using well accepted "best practices" to perform your role with the client. This will help you as you talk about what you have done you will also be able to discuss how you did it in terms that are known and understood.
3. If you can get yourself into one of the firms that you would eventually like to join as a contractor this is a good bet. Make certain that you don't challenge the status quo and act like a "company man" even though you are a contractor and not a employee.
4. Build up your own tool-kit of Intellectual Capital from your work as a independent. Be able to demonstrate some of this to your perspective employer and discuss how this will bring value to their clients and therefore to them. Of course on this one you have to be willing to turn it over to them for use.
But really I get back to the real question, why?