Tie down and anchor the portapotties, so they aren't blown over again by dust devils. Euw.
Get a base station with a VHF/UHF antenna on a mast, so we can get more than 8km range on our handheld radios.
Auto-updates when on wifi by phones and laptops causes massive data usage overnight, wiping out every block of data purchased. If we don't have Ka-band, then severely restrict net access.
Chilean customs is fastidious and expensive and in no hurry. Expect 2-4 weeks just to clear basic items on a carnet or as a temporary import. Expect lots of nit-picking about how to exactly format where weights and values go (top, bottom, besides) on any given listing.
Don't put on a carnet anything that can be easily broken, lost, or kept in country afterwards.
Ask for bulk shipments to be dropped at the field site.
Need better chairs, not flimsy plastic shells that collapse.
More fans? a refrigerator, 110V 2kW generator, large nitrile exam gloves?
Staggering the science team with the instrument team worked very well, both in building cohesion and morale among the subgroups and the whole team, without overwhelming the logistics for more than a few days. It fostered spontaneous investigations and ideas.
Next year, maybe the rover team gets staggered as a third group?
Having running (non potable) water and mains power was really, really helpful. Maybe get a water tanker or large delivery next year -- running back and forth to Antofagasta for 6x 5gal carboys every evening was a distraction.
Having a fixed, shaded structure in the hot afternoons was valuable for both crew health and workspace.