So the most important thing to make yourself attractive in in-house positions would be to continue doing what you're doing as a corporate M and A associate. That would probably be what I would recommend. Going to a more prominent firm would make you even more attractive. So the way that companies think is they typically want to have people that are from the more prominent firms. Because that looks more prestigious to their board and other people.
The more giant firm you're at many times, the better. The other way to make yourself more attractive would be to become a partner in your firm. Partners are also much more attractive for in-house companies.
So if you become a partner, many general councils of big companies have been partners and firms that could also help you.