The best time to establish good credit is when you have no credit. Before you sign up for your first credit card or loan, make a promise to yourself that will do the following:
If you have no established credit history, open a low cost checking or saving account and make regular deposits. Use credit cards carefully and pay them off each month
Keep a minimal number of credit cards
Keep credit card balances low, under 50% of your credit limit per card
Do not apply for a new credit card because you are at the maximum limit on the old one(s)
Pay your bills on time
Make at least the minimum required payment and pay down the balance when you can
Know your debt to income ratio and keep it to 20% or less of your take home pay
If you have a credit score that you wish to improve, it may take some time, but rest assured that it will go up if you do the following:
Have a budget and stick to it
Reduce or eliminate unnecessary installment payments like cable and new cars that may keep you from living off of your take-home pay
Make minimum payments on time
Understand that bankruptcy and foreclosure will stay on your credit record for up to 7 to10 years