First and foremost, location is extremely important when it comes to taking grad photos. For one, it's the easiest way to help represent the school, and it helps to make the photo more interesting. Therefore, it's best to choose landmarks at your school (such as the Campanile at Berkeley, or in general the main library). However, also talk to your grads about where they want to shoot. Often times they'll bring great ideas or want to shoot at their major's building. Also, try mixing in some scenic nature locations as well so there's a broad range of variety to the photos. This may require some scouting of sites beforehand, so be up for some adventure and don't limit yourself! Lastly, be weary of how much time you have, because you don't want to waste a lot of time walking from place to place, so try mapping out all of the locations beforehand to minimize travel time.