I'm having a rigify error after applying 'with automatic weights'. My character's hair is floating after I move around the rig and it's frustrating that I have no idea how to fix it. I don't know how to manually weight paint either. (I'm a big noob)
- Select your mesh and Switch to Weight Painting mode using ctrl+Tab
- Select your armature and switch to Pose mode using ctrl+Tab
- Rotate your head bone as shown in the figure you posted, which will leave the other parts of the head not moved.
- Now select your head bone and start weight painting using Mouse left click as shown below until all these parts are red, where these parts of the head will be assigned to the bone head and will move with it. You may need to turn off the limit selection as highlighted below