In art, it's easy to get carried away and want to just paint or draw whatever you're good at/whatever you want to. But, as tempting as this is, it's important to remember to always explain or show how you got to this idea. It is usually helpful to explore an artist and to explain what element from that artist you have decided to take away and use in your own work. Never try to skip to the end product - you need to take it one step at a time and develop something new each time, while being able to explain why you've done this and by explaining what it shows/what difference this makes to previous studies.
If you've done a particular study, take the time to think about why you did this the way that you did. What inspired you? Why did you use that medium? Why did you use those colours? What does it show? How does it make the viewer feel? In your annotations, be sure to address these questions. As I said, it is always helpful to be able to refer back to a previous artist. For example, if you used collage of words or book/newspaper pages as your background, you could say that this was inspired by Louis Jover, and you wanted to develop his idea as you wanted the message from the words to be a subtle message within the painting, but you still wanted the viewer to have to work to form their own interpretation - you wanted them to think, rather than giving them the answer straight away.