There are 3 credit bureaus, Equifax, TransUnion and Experian, where you can get you can get your annual credit report which usually stops you from going ahead with a purchase if it has a negative report on you, and allows you to purchase with no difficulty if your records are showing signs of positive credit worthiness.
The credit score is something that you should be careful about because it determines your ability to purchase things on credit, buying your insurance and even the opportunity to find a job may be affected by these reports. All your previous credit transactions are recorded here, and those late payments and default payments are reflected which totally affects your over all credit standing negatively. Worse of all negative report is bankruptcy which will hold to your report for a span of 10 years before it can be cleared. It will take time before you can fix your credit worthiness report because you will have to establish again a regular payment pattern which will be reported again to the bureau to generate another report.
You can pay you off your outstanding debt if that is possible for you so that you can clear your record of any existing obligation. If paying it lump sum is not possible, at least you can pay them on time. The unconventional ways to raise credit score simply clearing all your outstanding loans to relieve you from debt totally. This may sound too good to be true if this is real, but there is one possibility that you can change the situation and eventually increase your standing right away, this is to check your report against your personal file and find some inconsistencies. If you find any discrepancy from your report then you can inform them at once to amend that immediately.