If you want to create prosperity in your life, the first place to begin is inside. The thoughts and feelings you have about your life and financial situation do more to create your situation than any outer act you do. You can work 3 jobs and save every penny, but if your thoughts and feelings are about lack or "not enough," some force will come along and steal every bit of your hard earned money.
Your car may break down, you may discover you suddenly need very expensive dental work or the stock market may collapse. Whatever the situation, you can only keep the amount of money that matches your level of consciousness. If you always feel like you have enough, then you will always have enough. If you always feel that you have more than enough, your cup will runneth over. Your inner consciousness creates your outer reality.
If you've tried changing your consciousness about money and prosperity without success, you may have been trying too hard. When you try to change your beliefs directly by sheer force of will, you run into a lot of resistance. The harder you try to change, the more you stay the same.
Instead, try changing just one simple aspect of your consciousness. Identify a phrase you often say about your financial situation that indicates lack. For instance, you may say, "I can't afford that" or "I hope I have enough to pay my bills this month" or "I don't have enough time/money." When you notice yourself saying the key phrase, stop and say, "Cancel that." Say it out loud and mean it. Then express the situation that you want to create. For example, you might instead say, "I have more than enough money to pay my bills" or "All is well." At first you may not believe what you say - don't worry. Just fake it until you make it. Thinking new thoughts, like anything else, takes practice.
Why does this work? Because your key negative phrase is tied into an entire chain of thoughts and feelings about lack or poverty. Once you change the key phrase, everything else tied into the chain will also begin to change. In addition, you're tackling only a small area of consciousness so you won't run into a lot of resistance. The key is to be consistent in correcting yourself. Good luck!