First of all, mistakes are a clear sign that you are trying new things. It's always good to try new things because when you are trying new things you are growing. If you never try anything new, how can you improve? How can you expand? How can you innovate?
The simple answer is, "You can't" Look around you. With very few exceptions, either everything you see in your physical world or every single detail of single thing is the result of someone trying something new.
Another good thing about mistakes is this: when you are making mistakes, you are learning. Consider this: Edison failed 10000 times before he perfected the light bulb. When asked how it felt to fail that many times, he remarked that he hadn't failed 10000 times, but rather had learned 10000 things that didn't work.
But this all doesn't mean that you should forge ahead with disregard for the consequences of a mistake. Quite the contrary, when you try something new you have to be willing to set some reasonable limits so that, in the event that it doesn't work out the way you want it to, you will be in a position to try again.
We all have limited resources in the form of time and money so don't blow them all on one approach to a problem. Realize that it probably won't be perfect the first time and allocate these resources appropriately so you can learn, modify, and try it again. Only by embracing and using your mistakes in this way can you make significant advances in your business and your career.