How do I get a credit card with no credit history?

I am 18 and a student, I have applied for student credit cards at seperate times and have been denied because of having no credit history. The cards I am applying for are student cards for limited to no history, I want to know what else I need to do to get a credit card when I have no history. I want to get the card just to use for gas, so I can pay it off each month and slowly build some credit. Please Help!