Having minions rush around with all manner of lighting and flags and bits and pieces, and as many those as you could manage with the budget, the better. One of the well-known photographers doesn't even own his own equipment, it used to come from KJP / Calumet / Wex every shoot-day and was costed out to the client.
I knew of a photographer that would set up the entire shoot with strobes before the client even got there, and set the exposure to the fast possible shutter speed, usually 1/800th.
Then, when the client and ad firm came in, she would start rolling out 2K and 1K Arris, have her assistants run around lighting up the studio all day. Of course none of this mattered for the images; at her exposure, these lights would have no effect. It was just about putting on a show.
Now why would you need to do this? Well, if the client is paying you a $50K+ for a day shoot, simply setting up two or three lights is probably going to make them feel had regardless of how much they like the images.
On ad shoots we think a lot about entertaining the client and ad firm. A shoot is a normal activity for us, but for the clients it is a chance to get out of the office. It's a relief and break from the monotony. So yes, we need to entertain them. Put on some music, bull shit about other projects and life, buy them lunch (which was accounted for in the estimate), get drinks afterwards, etc.
Another photographer I know uses a profile picture that many non-pros don't get, a picture of him standing in Venice with a dozen other people from the ad firm's and client's office who were on that shoot. Now most will look at that and say, that's a bad profile pic, it does not really concentrate on him. But every person in that image has a smile from ear to ear; every prospective client will look at that image and think that he must be a great person to work with.
This is just part of the job.