Here are some basic, nuts-and-bolts tips that have helped our program run smoothly. Keep in mind that we have 34 iPads in one shared cart, and those devices are shared between 5 classrooms in grades 1 and 2.
Consider color-coded cases for your iPad. It is much easier for first graders to remember “go get the blue ones” than to remember “go get devices 13-18." We use the brightly-colored MiniSuit by Vizu, which is available from amazon.com.
Make the wallpaper image a jpeg of the device number. You can also reinforce the color-coding by matching the image color to the case color.
Have a landing pad for devices on top of the cart, and keep it clear of clutter. We put a colorful placemat on top of the cart. The mat is wide enough to accommodate 2 small stacks of iPads. Student tech teams need a safe place to put their stack of 2-3 devices down while they carefully slide them into the cart one at a time. They also need a place to set them while they are closing and locking the cart; trying to do so while holding iPads doesn’t work so well.
If your iPad devices are shared between classrooms, consider creating an electronic sign-out. We use a spreadsheet created at docs.google.com. We set the sharing permissions so that anyone could edit the spreadsheet, and then iPad teachers bookmarked the spreadsheet for easy access. (Only the iPad teachers can edit, because they're the only ones who have the link.)
Keep headphones in small crates or baskets on top of the cart, and keep a fixed number of headphones in each basket. Because each class uses 6 iPads at a time during literacy centers, we keep 6 in a basket. When kids come to grab the iPads, a "headphone helper" grabs a crate. We use the small and easy to store Califone 3060AV headphones. The cords are a bit too long, but we like the individual volume control.
Keep microfiber cleaning cloths in a basket on top of the cart. Have your student iPad team polish screens as they put the devices away. KlearScreen works great for extra smudgy screens, but if you have kids using this sprayable product, provide careful instruction so you don't end up with soggy iPads. If you have sticker shock on the KlearScreen website, a very slightly damp lint-free cloth is a thriftier option for ferocious fingerprints.
Appoint someone -- a staff member, parent volunteer, or older student -- to check the cart at the end of each day, ensure the devices are plugged in, and lock the cart. It's a lot of extra responsibility to ask the teacher who hosts the cart to take care of this -- especially when he or she is already putting up with the added foot traffic of student iPad teams.