I'm guessing you meant to type "Portraits"? It would make more sense if it were "traits," however. I'm not sure whether you are referring to traits which would be discerned from a formal personality assessment test, which would require you to do some research to find, or just traits in general. If the latter, then I would think attention to detail would be an important one; also, good analytical skills; good mathematical skills wouldn't hurt, either. And, although accountants are often portrayed as somewhat socially inhibited, it would actually be helpful, especially to an accountant in private practice, to have good people skills. Finally, I'd have to say that, in order to deal with the I.R.S. on a regular basis, it wouldn't hurt to have a sense of humor! :-)
I hope this helps!