TAS -> M7 -> IB - What should I work on?

I'm currently a Manager in TAS and was just accepted to Columbia's MBA program to start next August. My goal is to transition into BB or EB investment banking. My current specialization is healthcare so I'm thinking I'll probably try to join a healthcare group but may look into other options as well.

My main question to you all is what IB-specific skills should I work on to be prepared for internship interviews when I arrive on campus? Through my TAS work, I'm comfortable with running the due diligence process, leading management discussions, preparing quality of earnings (adjusted EBITDA) analyses, setting working capital pegs, and reviewing sales and purchase agreements. I'm also comfortable with CIM writing as I do a great deal of writing for our QofE reports.

The first thing that comes to my mind is modeling as we don't do much of that in TAS. I'll often look through our clients' models and understand the basics of them but have never built a model from scratch myself. I know I'll take classes on modeling in b-school but recruiting starts right when classes start so I don't think I'd have time to learn much before interviews. Do you recommend I take a modeling class prior to b-school or would this not come up as much in summer associate interviews? Additionally, what other skills/areas do you think I should work on to be prepared for IB interviewing and the internship itself?

Thanks for your help.