That is a good way to start, but keep in mind that a low credit limit can also hurt you. I would suggest getting a card with at least $1,000 and always use less than 30% of the limit. Keep your purchasing below $290 to give room for interest if you are unable to pay the balance off.
I want to also note that even a $1,000 limit is considered low by industry standards and the Vanguard score that you get from Credit Karma and the like, is not what most banks use. Most financial institutions use the FICO score. The Vanguard score tends to be higher than the FICO score.
