Guilherme's comment is a good one. I'd just like to add: standing up for your designers, particularly in client calls/meetings. Can't tell you the number of times I've been all-but-thrown-under-the-bus in front of the client. Backing up your designer's design decisions (his/her area of expertise, after all) is really important, both for how the company looks and for your professional relationship. I automatically give 2x respect points to POs or PMs who champion design alongside me.