I like to get to the trial early if possible and that is not always possible. Having someone walk the course is definitely valuable. More important to have some one walk, than walk it yourself. The way it looks from the post is more relevant than what you can see from the cross drive. I like to check out how the pen works. It is a terrible nuisance to be surprised there. I clarify in my mind the pattern of the course. No one likes to turn the post the wrong way deliberately.
I do not get different dogs ready in any particular way. My whistles are the same, lucky for me.
I like to see runs.
It cannot be a disadvantage to know more about the sheep, where they are leaning; how much dog they like; how much handler they will take at the pen. Some sheep like people.
My dogs tend to be very capable sheep spotters so there is no need to get them out early. If the outrun is tricky, sure, I give them a gander. On the other hand, they are very relaxed watching other dogs working so there is no worry for me there. I get them when it is convenient.
My plan is to bring in the sheep in an orderly fashion and hit all the gates. I do examine the drive line from the handler's post to drive away. Being aware of it, improves my chances of a good post turn, with a line direct to the drive away, dog stopped in precisely the right spot to effect that.
I can plan all I want, but the best handlers forsake all plans and get flexible and responsive to immediate circumstances at the moment they present. Timing is everything. Preparing yourself with good timing reigns.