Hairbrushes
Once you’ve found a brush that doesn’t make your hair frizzy or flat (depending on your particular annoyances), then you want to hang onto it. The problem is that, like many of the things on this list, it doesn’t last forever.
You should be changing your hairbrush every 6 months, depending on the brush’s condition. Pay attention to whether the bristles are coming out, or the bed is cracking. You should also remember to keep it clean. Washing it in shampoo and rinsing with warm water is the best way to do this, and some people even resort to dunking it in a glass of alcohol overnight.