Pay all of your monthly bills on time
Don't go over your limits on your credit cards
Save some of your paycheck each month
Spend less than you earn each month
If it is possible, get a 2nd part-time job to pay down some of your debts a little quicker
Are you considering taking out a personal loan to buy a house? Or just in general want a personal loan for something else? I have a strong financial background and could possibly give you more specific help, but I need more info.