I used the waterproof/fitted pad layers on at first...but honestly, quickly found that they really didn't do much good. So, after about two months of being in the crib (she was in a bassinette for the first 6 months, so she was like 8 months old) I just used a fitted cotton sheet. It is SO much easier to make the crib up with just a sheet...no more pinched fingers trying to squeeze all those layers down the sides. Hope that helps! Oh, and no blankets until one year old!!