Bills
Chances are that your biggest costs will be rent and bills. There is not much you can do about rent, but look at your bills. Is there a cheaper supplier for your gas, electricity, internet, phone, TV, mobile? Some people seem to have high brand loyalty, even when they face poor customer service and high bills. Compare different suppliers. Could you save money if you switched? Try not to look just at money. It is not worth saving a few pennies if the service is unreliable or it takes ages to be connected. And try not to go entirely on a friend's recommendation. They may, for example, find XCellphone is cheaper, but maybe they talk a lot more than you and text less. There are lots of price comparison websites out there, have a look for yourself. You may find a more reliable supplier for less money. If so, and you are out of contract, then switch and see how much you save.
Cash or cards?
How do you deal with everyday purchases? If you check your balance regularly and find that taking out $20 means you spend $20, whether you need to or not, then paying by debit card makes it easy to track your spending. On the other hand, if paying on your card means you spend money you don't mean to, take some money out and make it your budget for the week, or next few days. Switching payment method may save you money.
Transport
Transport can be another large cost. If you are on a budget, can you afford to run a car? If you are very isolated, or need a car for work, there may be no other option. But if you are in a city with good public transport, then look at it honestly. It is too easy to just look at petrol costs, but take into account insurance, the cost of repairs, car washing, any likely future maintenance and, if you can, put aside a little for any emergency or unexpected repairs or accidents. When you have taken all this into account, is it still worth running a car?
If you already take public transport, is there a cheaper way of doing it? Many bus and train companies will offer discounted travel if you buy in advance. If you have the money to spare, buying a season ticket can be worthwhile. If you do not have that much to spare, look at shorter term options that may be there, like ten journeys for the price of eight or combined tickets for buses and subways or trams, if they exist.
Alternatively, could you bike or walk? If it is only a short journey, walking may not take much longer than driving and finding somewhere to park, or waiting for a bus.
Taxes
Are you on the right tax rate? If you are paying too much tax it can really add up over the year. If you find you have paid too much, organize a tax rebate. If you are not on PAYE, but file a tax return at the end of the year, make sure you have properly budgeted for this. If you pay your tax at the end of the year, work out how much you should put aside each month and put it in a savings account. That way you earn interest on it and get a nice bonus at the end of the year.
Reclaiming bank charges
This is a big thing at the moment, and can be worth doing. There are companies who will reclaim the charges for you, useful if you are very busy or not very organized. They will, however, take commission. If you would prefer to do it yourself, there are numerous sites with model letters for you to copy and send to your bank. There may be strict time deadlines in returning letters, so make sure you keep on top of it.
Credit
Credit can be a dodge-y issue when you are on a budget. Buying something you need and spreading the payments may seem sensible, but look at how much the item will cost by the time you have paid interest on it. Store cards are generally a bad idea, as the interest can be very high. If you open your account for a discount, be very careful that you are not tempted to make further purchases which can soon spiral out of control.
Magazine subscriptions
This may seem a strange one to include, but make sure that you actually read any magazines you subscribe to. If not, cancel them. It may only be a small amount every few months, but it is easy to forget about and can lead to you going overdrawn.
On the other hand, if you regularly buy and read magazines, a subscription may be a good thing. It will save you money and mean that you do not pop into the newsagents and buy a can of coke and mars bar while you are there. Just take a note of when the payments come out.
Loyalty cards
If you regularly shop somewhere, it can make sense to have a loyalty card. Just make sure you use the points. Some places will have offers, like 500 bonus points if you buy a certain item. Do you want the item and will you spend the points? Some places make it quite hard to spend your points, so look at how easy it is to claim when you start. In my student days I quite often lived off my points at the end of the year.
Vouchers
You may well get vouchers dropped through your door every day. For students, go to the Freshers Fair and you will get lots of money off coupons. These can be great as places will often offer substantial discounts to get customers in. Just be careful you are not buying something you otherwise wouldn't, just because you have a voucher. Throw away any you do not want straight away. It saves clutter and will stop you buying things you do not need.
Keep track
If your bank offers on-line banking, then sign up. This means if you have an unexpected bill, you know it has happened. This way you don't face any nasty surprises. Some people say they find opening bills depressing. It's far more depressing to find you are being taken to court. Make sure you pay your minimums each month, and pay as much extra as you can. If you have a large bill, pay as much as you can when you can. Call up the person billing you, and arrange a payment plan you can stick to. Do not agree to pay more than you can afford, as this will not help. Be pro-active rather than trying to ignore money problems. They do not go away and frequently get worse. Taking a little extra time may mean the difference between managing your finances and losing control. Good luck!