It was only a few months ago that I found out about homemade veg stock. By freezing the ends and scraps of your veg until you have enough to boil in some water, you can create vegetable stock cubes by putting the infused water in an icecube tray!
This works well even in a student freezer with limited space and you can keep the scraps frozen until you are ready to make your next batch.
Then of course the discarded scraps can go in a compost heap or your food bin.
You can use anything from carrot ends, to poatato and onion skins!