If it is going to take a long time to save up make sure you save it in an account with high interest.
Most people finance their cars, paying 10% or more down. Working on your credit rating ahead of time would help you qualify and get lower interest. Even a 'secured' training wheels credit card that you prepay is a start.
Inculcate the habit to save first and spend. When you receive your monthly salary, save about 15 - 20% and spend the balance amount.
Pay yourself first. Any paycheck or money you get, stash some away for yourself in a place you can't easily access, before you pay any other bills or spend any money.
