Count policies vary radically. As a circulator, you could be the anesthesia tech (setting up all lines, assisting with aline and PA insertion, attaching and hooking up all monitors, and even getting all anesthesia drugs before and during the case). You might also be the person setting up and running the cell saver, and the foot pedal for the saw (nope, even today not everyone uses battery powered saws). Drugs delivered to the field may vary from what you are used to, protamine for example. Minimally invasive and vein harvesting equipment also vary quite a bit. Robotics!
There is quite a lot of variability in surgical technique and equipment. I was blown away at my very first assignment at Duke in 1995 because they did the proximals first off pump. This technique required extra vessel harvesting and we stored the excess sterilely in case of bring backs. They also used a laser to punch holes in the ventricles to increase perfusion for selected patients who were not grafting candidates. This was a long time ago, and I have not seen either practice after that. This is just an example of how you may not be in Kansas anymore when you start traveling.
Keep an open mind and recognize that whatever you are hit with does have a history of success and safety at that hospital. Don't assume you know it all. Project flexibility and adaptability at the interview and on assignment and you will be successful.
Some surgeons are incredibly... umm... fastidious, affecting all team members. Especially if you scrub, you will have to adapt. Not always easy and they will want it done one way - their way. One assignment I went to in Charleston West Virginia had 17 surgeons and I spent the entire assignment scrubbing. Not as hard as that might seem as most surgeons were in two groups with standardized opening and cannulating stitches (more or less), plus a couple of independents. One surgeon, the infamous Dr Malek, had hands that were "delicate instruments", and you had to pass like his hands were eggs! I had fun at most assignments. But then I tend to find difficult surgeons amusing.