i didn't get a credit card until my 3rd year of college and i use it mainly for larger purchases, but my limit is only 500 dollars. i dont have a savings account so i mainly make a largish purchase, ie wheelset, crankset, tattoo, ipod, etc. then pay off 50 or 100 dollars every paycheck. when im back to 0, or under 100 anyway i will make another largish purchase, if theres something i need/ want. i try to stay away from using it for things like food, or small purchases because thats harder to keep track of, and definately not for drinking. i always keep enough money around to buy extra things like tubes/ tires as needed. i do tend to find that i'm happier spending a large amount of money towards the beginning of my pay cycle and figuring out how to budget my life with less, than wasting a bunch of money on a few highish bar tabs and not being able to afford things i would rather have than a hangover.