What kind of consulting are you talking about? Assuming strategy... Graduate education (MBA, JD, PhD) + MBB. Cerfitications are meaningless in this field of work.
If now you are talking about specific consulting, things are different. A CFA or CPA would obviously have value for banking / investment / ... consulting; an MD would be valuable for Healthcase. These aren't certifications however. Perhaps IT cerfitifications for an IT company? In general though, I view certifications as degree-lite programs -> short amount of time invested in getting that piece of paper, and low value. Your best bet is still a long list of happy clients.