1. You have to tip the bagger. I had been told that ahead of time so that was nice. But they do expect it, so make sure you have cash on you.
2. Make sure you have your I.D. out when you go through the line, because they will ask for it and you don't want to have to rummage through your purse for it.
3. The commissary has only food and items related to that (detergent and cleaning supplies are there too) but everything else is at the PX. So they have most things Walmart has, just in two stores.
4. Most things are a cheaper there. i don't know if everything is, but most things are!
5. Make sure as you are walking through the parking lot you are conscious of the reserved parking spots. They are the 5 (or so) closest spots and are reserved for those of high rank (i.e. generals) and as you walk by them watch for people parking there, just walk on the opposite side so that you give them room to park and aren't in their way. It's just an act of respect.
Altogether, my trip was a pretty good one. I get several bags full of items and it didn't exceed a hundred dollars. it was really nice!!