Steal toilet paper from public toilets and the university toilet. In one of the cubicles, take a hacksaw and quietly saw a straight line through the paper. You will have to strike several places in one go since they will put up measuers to stop people from doing this.. Thankfully, you can probably steal half a year's worth of paper.
Don't drink soft drinks, juice or alcohol. Instead, take a large bottle from the garbage, clean it in a public toilet and refill the bottle with water. Your health will benefit from the absence of unneccesary sugars. Plus, as a student, your mind is your most profitable commodity- so you should protect your brain by abstaining from alcohol.
If you live near a park or public toilet, fill up buckets of water from the tap there. You can use this free water to shower, flush your toilet and clean the house.
Don't buy any trendy clothes. They're expensive and will go out of fashion quickly. Pick something that lasts, like a business shirt or some slacks.
Save on paper by using the backs of waste paper.
Buy secondhand textbooks. Poor quality textbooks are cheaper, and still useable, just make sure its not unreadable. Ensure you buy a relevant edition.
Girlfriends/boyfriends are expensive. Don't get one. If you can't control yourself, then try to limit the relationship to cheap thrills, like watching the tv at home, cooking dinner together or whatever.
As a uni student, you usually will travel alone. Buy a moped, which will handle the majority of your needs with a great fuel economy.
Spend all your time either studying, working or at uni. This stops you from going out, where you will spend lots of money. It also has the added benefit of making money, if you spend he time working.
If you are attractive, prostitution is an excellent way to handle most of your expenses. Swallow your pride and just do it.
Don't eat out. Always eat cereal for breakfast and a sandwich for lunch. For dinner, make something cheap and nutritious at home, and in huge batches. Something like pasta or rice.
