A single month afgter opeing, my scores went up 64/68 points, from the 598 range to 665 range. Keep a low balance or utilization rate of less than 30% (preferrably less than 10%). Studies show the sweet spot is 1-9%. Paying on time 100% of the time and knowing the date your card reports the balance to the credit bureaus is the key. Always pay by the due date and be below 30% (or 10%) on the reporting date. After as little as 6 months, but usually 12, they will convert your card to UNSECURED, likely with a limit increase and give you your original deposit back.
Next, estimate your monthly spending habits for other expenses such as gas, groceries and entertainment. Create a limit, based on your income, of what you can spend in each of the different categories of expenses. For example, if you tend to spend $400 a month on groceries, try to stick to $300 a month on groceries by making changes like buying generic brands, using coupons, and resisting impulse purchases.