On FM11 I was able to bring Arsenal's massive £10M+ losses per month down to £1.5M losses, making an overall £50M+ profit at the end of the season.
1. Sell off any fringe players on mid-to-high wages. Gains transfer money and drops wage budget.
2. If a first-team player is on high wages but is replaceable, then sell him.
- I remember (on 11) selling Samir Nasri to Valencia for £20-25M and that dropped my wage problems by a good £110k p/w.
3. When offering new contracts, always drop the wages and negotiate for the best deal. On FM12 I have managed to get Rosicky to take a £10k p/w wage drop.
4. Remember that all contracts usually come with clauses and sign-on fees. Keep these as low as you can.
5. Try and pay off all transfers with your budget, and stay clear of monthly installments. Although these are spread out over a longer period, there is a reason that your board gave you that certain amount of money.
Try those steps, and see how it goes. There are other tips as well, but I didn't want to go on for days about them >.<