Self Portrait - Side and 3/4

I'm learning a lot from Drawing on the Right Side... especially about the importance of details, relationships and sighting when drawing portraits. I'm struggling a bit with portraits. I tried a sketch of F.D.R. because I found this great photo that I though would make a good sketch. But after about 5 attempts, I gave it up as lost. The tiniest detail variation can make someone look like an entirely different person...

So, if nothing else, I've learned that anybody can draw a halfway-decent human, but to really make it represent the subject takes incredible attention to detail.