The first thing to do is to cut up your credit card/s. This will prevent temptation to spend. Then sit down and write yourself a budget, listing all your non-negotiatable outgoings on one side, (rent, food, fares to work, etc) and all your pleasurable expenses (toiletries, dining-out, etc) on the other. Then see what can be cut out. If you manage to do without it, every day put that amount of money away and use it every month to reduce your debt.
Don't take surplus money out with you, and keep a daily expenditure diary. You may be shocked to find how much you are actually spending on non-essentials. And try to reduce your most expensive debts first.