Our first instinct after FINALLY getting a paycheck for the work we are doing is to go buy something to reward ourselves. If you want to buy those $200 shoes or take your girlfriends out for pedicures, go for it! You deserve it!
But before you go buy a new MacBook Pro and take out a Mac credit card or go new car shopping you should wait a few months. Get several paychecks under your belt and the timing of those paychecks before making a big investment. Just because you've seen a salary written on a contract doesn't mean you have your finances totally figured out. Wait a few months until you've been able to pay all your bills (including your student loans... ouch!) and are able to put some away in savings before you tack on another month payment. Once that car is in the garage you can't take it back so you have money to go on vacation with your friends.