Here are a few tips that will make you financially responsible while you are in college:
a) Set a monthly budget and track your budget diligently.
b) Anticipate the unexpected (e.g. your car may need an emergency repair) and set aside money for such unexpected expenses in your budget.
c) Control your "impulse buys". Whether you are in a store or buying something online, don't just buy something on an impulse. Rather, sleep over it for a night or two and ask yourself the following questions:
Do I really need it? How will my life change after I buy this? Will it make me happier? Will I really be using it as much as I think I will? What other priorities do I have that I can spend this money on?
Once you answer these questions, you will make a more rational decision on whether you want to make the purchase or not.
d) Get started on learning about saving for the future. It will be good if you can actually set up a savings account and start contributing to it.
e) Try to limit your student loans. You will ultimately have to start repaying the loan when you get out of college. The lesser you borrow now, the lesser you will have to pay back after you start earning.
I hope these tips help you get fiscally responsible.