For me it depends on the paddock size, expected attendance (different for each track and date) and anticipated weather.
I have a 6x12 enclosed, and if it might rain, I try to set up one EZ-UP so that it's against the side of the trailer so I can cook and get stuff in and out the side door without getting wet. I'll also set up the second 10x10 EZ-UP (when there is room) if it seems like it will be wet, or if I have someone along with me (and there's enough space).
My ideal setup is to pull in so the trailer back is about 10-15 feet off the road (the actual travel path, not necessairly the pavement), and have two 10x10 EZ-UPs, one at the rear and to the right of the trailer, butted up against the second one which is alongside the right side of the trailer.
I use 5 gal buckets as hold-down weights, I just fill them with water from a shower or tap. Lighter to carry and compact to store. (Stole this idea from ButchF ::adore: )
I try to plan my pit for maximum protection from the sun as it travels across the sky, so if I can put my trailer on the south side of my pit, that's best, as it acts as a shade, especially in the spring and fall when the sun is further south.
If I'm camping, its either the tent or sleeping in the trailer, depending on how hot it is (hot=tent) If I chicken out and get a hotel or am at Putnam (no camping) I usually pack up the trailer and leave it. Again, depending one weather expected, I may leave the bike(s) under a EZ-UP and lower it to the lowest height and tie it to the bikes for overnight.
Not sure I have access to any pics. I'll check and post them if I can find them.