THE MANAGERS. They're generally good people. I really did like most of mine. But they're so strained on resources that half of them clearly didn't even care anymore and just sat in the office, and the other half were in overdrive at all times, breathing down our necks and yelling at us in front of customers. If an employee made a mistake or asked a question they somehow should've known the answer to (which happened multiple times, due to the ~2 hours of "training" we had), the managers would ridicule them on their headsets so everyone could hear. It made most of us avoid asking questions out of fear and end up giving customers the wrong information.
Also, the visits from corporate seemed to strike some kind of ungodly fear into their hearts. Even the laziest managers would suddenly become high strung and yell at us for not sweeping, doing returns and five starring quickly enough, knowing that we were completely understaffed. They're too scared to say anything to the higher ups and personally, it made me furious.
TRAINING. Please invest more than just a few hours into your new employees. My first day, I stayed in the back and finished Michaels University on the computer. The manager rushedly went over VERY IMPORTANT things like the credit card/gift card policy before rushing back to the floor. After that, I ghosted a cashier for about 15 minutes before being put on my own register. It was a "trial and error" process for every employee, which obviously frustrates the customers.