I don't know about skills, but I would recommend cutting everything on your profile before "I specialize..." Clients can read your reviews, and they already know your name. They don't care where you got your degree. They care what you will do for them.
What skills do you feel you are lacking in? We haven't seen your work, so we can't advise you on what to study. Maybe look at your clients' feedback that has been less than stellar and brush up on those skills that were lacking? Seems like a good starting point.
Good luck!
