Well it's an index card. You can't really improve it other than it's flimsy/non-flimsy structure. It's one of the most basic office/school supply and you can't really do much for the design. The staples brand index card was a great price when I bought it but the quality of the card was not so good. They're too flimsy but for it's price I can't argue too much.
I have a mini-binder that I use for my team. I am in lower management and have a rotating crew. The best way to keep track of my workers is to keep notes on them - when they're up for promotion home info such as phone numbers and anything urgent projects coming up in the future. These are handy enough to carry with anywhere inexpensive enough to keep notes on everything and help keep me organized as a team leader.