I started out using cards/sheets similar to the onese on medfools - would carry them around in my pocket. I've never used clipboards, as I'm sure I would leave it behind somewhere. It's also easier to just have everything in your pocket. I never carried anything heavy (besides a small handbook), so my white coat was manageable.
Now, during residency, everyone uses "scut sheets" - every service has a list of patients that we print out daily, and we write important vitals, labs, to do lists, etc. on them. Much easier that way. Eventually, you'll remember most of the details on all your patients. I'm always amazed at chief residents who can instantly recall minutiae on any one of 20-35 patients.