My little rant on things to say to your girlfriend
The most commonly used one and another good source of inspiration is food. You can choose from sweets, like cupcake, or you can choose from fruits, such as strawberry. Your girlfriend will love that you see her as sweet and cute as those sweets and fruits. But make sure not to call her anything that is connected to heavy meal, like pork chop. She will think that you see her as fat and she will surely not see that as cute.