A big red flag for me is when I encounter a leader who is always sitting behind his/her desk or always in meetings in their office. I am also not a fan of a constant open door policy, but having your door closed all the time is much worse. You need to get up from your chair, walk out of your office and circulate amongst your employees. In addition, you need to also be out in the field regularly meeting with your top customers and business partners. Leadership is an active not passive activity.