Building positive credit is a difficult task, but it's not nearly as hard as repairing the negative credit. Several public schools and universities are just now trying to teach our children what credit and credit history is all about. There is quite a long way to go still, but there is some achievements that can be seen.
One of the first accounts of credit a young person receives is often times buying a car. This first credit account is where it all begins. If a mother or father has a great credit score or FICO score and cosigns with the child, it helps substantially to receive a low interest rate on a car loan. But, sometimes the single most important factor of building up good credit is to make sure the loan is paid on time every single month it is due. If possible, pay a little in advance.
For the most part, credit cards are pretty easy to apply for and receive. They are almost too easy to get, but that is a story for another day. Anyway, the point is that there are easy ways to build a positive credit history quickly. Most credit worthiness is determined by the level of available credit you have opposed to the amount of debt.
If you have a credit card that has a $5,000 limit but your balance on it is, say, $400, it would be a very good credit-to-debt ratio. Lenders like good credit-to-debt ratios. Credit reports that have great ratios are very nice to have. Having a past history of making payments and paying off a full balance on a card by each billing period due date will help greatly to build that great rating quickly.
Maintaining a good history is difficult. Life does happen. Individuals can get sick or injured. They can lose a job through no fault of their own. When bad things happen, the best thing to do for a credit report is to talk to creditors. Explain your situation and most creditors will work with you and will not file reports with credit bureaus that damage your credit rating.