What is it? Talking to management who already knows what needs to be done, telling them that they need to do it. Providing your stamp of approval so they can go to their board.
Advising clueless management that don't want to ever change anything. Coming up with a 150-page recommendation that would never be implemented, using complicated buzzwords nobody understands like 6-sigma and lean manufacturing.
Liaising between buyer and seller who already know what they want to do and at what price. Coming up with a 50-slide deck and 300-page prospectus (which is 90% copy-and-paste job) justifying the transaction and price.
Screening 200 potential investment leads, searching for gems. Eventually realizing that the good companies don't need your money and that the ones that come to you are in terrible shape.
Building an Excel model in 2 hours with super simplistic growth and margin assumptions, using house template of course. Coming up with a story line to accompany your calculations. Checking with other research houses regularly, to make sure you're not saying something completely insane. Adjust the numbers upwards if the stock goes up, and vice versa. Goal seek everything.