My experience told me the most important thing on NIW is the recommendation letters. When filing NIW in 2004, I did not have even one paper, with which I was the leading author. However, my petition was approved after re-submission of ETA750B, which I did not know it was required for NIW (Of course, I would not have that problem if I had hired a lawyer.) My suggestion is that doing all things by yourself. You don’t have to hire a lawyer. The reason is that you the one who really know your background/research work best. You know exact target to shoot. My suggestion is that if you don’t know what documentation is required for NIW petition, you may want to hire a lawyer. If you know exactly what supporting material you need to submit, DO IT BY YOURSELF!