After carefully considering the OP's question I feel what black men really need to do, is what all men need to do and that is to simply accept their size. I'm 6'4 broad shouldered, muscular body and most of the time when people interact with me they always want to drop a hung penis joke my way. It's almost as if, because I am both Black and Tall that the odds should be in my favor. In my youth I must admit this was an uncomfortable position to constantly be in. I felt as though I was expected to have a 11 inch penis. To be as thick as a beer can and yes it did cause anxiety for me cause I wasn't.
However, one day in high school a mixed group of us both girls and boys were talking and we asked the girls what they considered big and their answers shocked the guys. They were like 6 or 7 inches. We were shocked because we were all thinking 12 / 13. It was an eye opening moment for me because I realized that the concept of size was all relative. I were putting pressure on myself to live up to an expectation that quite frankly I had bought into, convincing myself that I were inadequate.
Furthermore as my sexual experiences increased, I learned about technique and the fact that like men's penises every vagina is not the same and is not pleased by the same position, stroke and ridges of the cock. Learning that a woman can go into sex with a man thinking I need it to be huge and then be pleasantly fulfilled by his stroke lessoned the importance of size to me and refocused my thoughts on not only accepting my size but learning how to use it.
I've since grown to love my size not wanting it to change and I think when the individual is able to let go of their own perceived expectations of what they should be and accept the joy and benefits of what they are then it doesn't matter what anyone else's perception of them are and what others think they should have.