A lawyer I coach asked me what was the most important client development skill I worked on to perfect. I did not hesitate, answering:

Presentation skills

I know I attracted more new clients by my presentations than any other thing I did. Why? When I was presenting, potential clients could easily evaluate my knowledge, my ability to make the complex simple and my personality. But, here is the most important point: I practiced presenting, over and over again. When video cameras first became available, I taped myself presenting.