Your question is a great one and very particular to the level and quality of play.
At the youth level of say twelve (12) and under, I can only guess at how a youngster is "prep'd" on game day - if at all. But then again, I'm only guessing.
At the high school and Legion level I'd assume who's ever available for coaching and the experience and resource ($) that are supporting the program would have a lot to do with that answer.
At the community college/Jr college and the formal four year college, again it would depend on the resources and focus by the coaching staff. Some programs are very deliberate and dedicated, while others are casual - even during their best moments.
Here's what I've done:
I've had a "shared " resource program with other sports and even with my fellow coaches, for gym use, field use, training room (circuits), and scheduled trainer's time.
Having a resource base to work off of, I know what and for how long I can compliment a rotation's multistage involvement. And how to insure that every single player participates when and for how long - to my satisfaction. I also have assistants and interns that I'll use during the process to spread the "look see" feedback.
During the prospect process of sitting down and interviewing/meeting with my potential and returning players, I cover a "what's expected" by giving them a worksheet of training routines, basic rotation protocols, and a host of other things so no one says to me at the eleventh hour " hey coach, no one told me!"
After the final selection process, a meeting is held and every single pitchers is expected to "agree" with the rotation mindset of what's required by them - how - when -n- why. Staying healthy, staying focused, preparing for an appearance far enough in advance so no surprises hits me or the other coaches.
Since I've had an agenda well prepared during one season - well ahead of the next season, I'm kind of set in my assumptions of a GENERAL rotation make-up, I know I should have the guys to carry me with the maturity and self awareness of what they need to do when given a rotation schedule far enough in advance - but - tailored to fine tuning when the need arises.
The day or night of a game, notice far enough in advance has been given at least five (5) pitchers to "ready" themselves. This is not to say that the rest of the bullpen is sitting on their pockets playing mumbly-peg. (those that are not "posted in" are on rest form prior appearances)
Now here's the trick - after a review of who we’re facing and what that club's hot streak is doing and especially WHO, the "ready guys in my rotation are usually found five(5) to six(6) hours before game time at the field walking around, getting familiar with the surroundings, and just fitting in mentally and relaxing the butterflies. Some guys will even take a hot shower, get a rub, and do some stretching, jog around the field, while others will study the view from the mound.
The entire rotation will meet for a short period to go over who we're facing and the latest "scoop" of who's hot and who's not, best pitch selection for who and why (sometimes), and finally I ask ... "how's everybody feeling?"
As a rule, I don't meet with my starter and who I have to use if I have to go deeper into the rotation. These guys are usually in their own space anyway.
Now here is the part that's different for every guy. Some guys need at least twenty (20) or thirty (30) minutes to get "into it", while others need substantially less. I say this because highly talented pitchers that have been given an "expectation" schedule, should be mature and competitive enough to know their own preparation prior to an appearance. And on that note - transportation to and from the game is either provided for them OR they provide their own ... in any event, it's up to them to make the showing - PREPARED. I don't baby-sit anybody. But then again, all this is covered way before a guy comes on board with any club that I've been with and charged with the pitching staff.
During the pre-game bullpen duty, my starter usually finds a surface that he’s accustomed to starting
with. It can be a flat area at first, then he can go to a gradual incline, and finally finish off his warm up on a mound in the bullpen. In many cases, a pitcher will start at say .. thirty(30) feet, get his body working and find his target and repeatedly work it (target). Velocity is usually well below game speed at this distance. As he limbers up and settles in, he moves back progressively and customs his workout to what he feels best. I should mention that a lot of guys that I’ve seen do not go through their pitch selection during this “initial” phase. However, when a pitcher moves into the bullpen proper, this casual phase ends.
My bullpen catcher has a “Pitch Sheet” specific for every pitcher. This “Pitch Sheet” contains the pitcher’s name, and his pitch inventory. So, when a pitcher is ready to start his serious work, he alerts the bullpen catcher and a percentage of effectiveness is noted for all the deliveries from that point on.
For a fastball by location, what’s the percentage of accuracy for - high left, low left, high right, low right, and consistency on velocity. Other pitches are also pegged. This kind of information is invaluable for per-game estimates of what’s working and how well. Hence, if a down and in for say low left is just not on this day, for whatever reason, the catcher and I, along with the infield coach(s) and our head coach, know that this is out of the mix for this guy. Basically, what we’re trying to get as many “knows” for the game as possible, in addition to getting our guy ready to the day’s work. And here’s the importance of this mindset – during a game, pitching coach don’t coach … they manage. During a game a pitching coach doesn’t have the luxury of addressing mechanics in depth. Subtle adjustments …
well to an extent … but I rarely go there myself. Other pitching coaches have a different approach, as would be expected. On the other hand, long before a guy gets into trouble, I have somebody up in the bullpen just ready to get in there and do their thing. And it’s funny how some guys will come around when they causally glance over to their side of the field and see two guys in the bullpen warming up. As for me, I don’t this deliberately to get that kind of recognition.
This probably doesn’t address the specifics of what you’re looking for, but I thought I’d give you a general idea of what’s out there- from my experience anyway.