Credit score gets updated with a single change in the
factors affecting it i.e. payment history, new credit, length of your credit
history, amounts owned, and types of credit. Since they are calculated on
your current credit history, you can improve it by strengthening the week factors
in your report. There isn't any
fast way to improve your fico score, as efforts for such a fix usually backfire,
so I advice that you should follow the following instructions

Payment history

If you successfully manage your finance you will be able to pay the monthly
payments without missing any and on time.

• FICO scores get affected by payments that exceed 30 days appearing on your credit report as late payments. For example, a bill is issued to you on 1st of a month with a due date of 15th. If you are unable to pay your bill with in the due date you will be charged extra interest but if you are unable to pay before the 30th of that month, the late payment information will added into your fico score. So, pay them within time.

• If you pay any delinquent payments or collections then that will not improve
  the score. Such information remains in your report for 7 years. Try not to
  have default accounts that may lead to such a situation.

Amounts owned

• FICO score also gets affected if you keep your balances on all of your credit cards high. If you keep them between
  25% and 50% of your available credit then you are considered a responsible
  borrower. If you have higher balances then your debt to available credit ratio
  is raised which badly affects your fico score.

• If you transfer all the accounts to one account, you don't raise the score. In fact if you pay off every individual account your score rises.
• Closing all the credit accounts that you don't use to raise your fico score doesn't
  work either.

• Try to maintain 3-5 credit lines, as without a credit line you will not get fico score improved. This will be enough for a personal score. If you still want more credit you can ask for a raise of limits on these accounts rather then applying for new ones.

Length of Credit History Tips

• FICO score is affected if a number of accounts are opened in a very short period of time. What happens is that the average
  age of your accounts reduce and this will put a negative effect. The longer is the average age of your credit lines the better it is.

• If you have a $0 balance then that credit line will not show up on the credit report. It is good to keep $10 dollars instead and don't pay off the whole thing each time.

New credit

• FICO scores count only one inquiry for all
  the credit inquiries made over a single loan within 14 days. Don't let too
  many inquiries to appear on your score as they lower the FICO score. Shop
  very wisely.

• Get new credit lines and start paying them properly. This will increase your credit sore.

Types of credit

• You get a great FICO score if you are able to handle mix credit at the same time. In general, these are installment loans like auto
  loans, personal loan or mortgage.

• Your FICO score will boost up if your revolving credit on credit cards likes, Visa, MasterCard, Sears, Sunoco Gas, Costco credit cards, are mixed properly and show that you can manage them. You can do that easily as you get short and long term credit with fixed payments, as well as variable payments.

More Tips

• Get a copy of the report. A personal copy doesn't put an inquiry in your
  credit history and has no affect on your FICO score. If you find errors
  in it then write a dispute
  letter, along with the proofs, to the credit
  bureaus to fix them. If you don't have the proofs send them anyway. Credit
  bureaus are responsible to validate your claims. Your credit score is greatly
  affected by these errors.

• Your FICO score gets damaged to great extent by bankruptcy
  filing. The bankruptcy information
  stays for 10 years on the credit report and decreases your overall score.
  In case you declare bankruptcy then everything has not gone bad. The older
  bankruptcy account becomes, along with a rebuilt credit history, the less
  of an impact it has on your credit score.

• To boost your credit score you can also add your account into someone's account. This relationship is based solely on trust. Their payment history appears on your credit report too. If their account is perfect so will be yours. All this trusted person has to do is to get an application for adding a card holder. Once the application is accepted their entire history is represented in your credit report. The real deal is to find such a person. People will not bother to add you in their accounts especially when you have a bad score. But if it certain facts are clear to that person then he will add you on his card holder list. First he will never have to give you his pin number or any information, the bills and account information will be mailed to his address and you will not have any clue about his account. This can land you many such people and you can boost your credit score.