As a photographer I will never shoot anyones portfolio without having them sign one. Even if it is for their own use, you still own the rights to the photographs you take.
You can download these forms using the links below, it is a simple form with basic information but covers the photographers well enough without scaring your model.
Model Release with Parents signature for minors
Model Release with just the models signature
Feel free to modify according to your needs. Do leave a comment if you have any questions or concerns!
Disclaimer : I am not a lawyer and do not hold any responsibility if someone decides to use these templates!