I am just a low level businessman who manage small business. But Alhamdulillah, through this business I can fulfill my family need and can employ several people. It's means I can give income to other people too. However, actually this business was not a business which I've planned before.
I've ever made big mistake in business that made me fell into bankruptcy. Then I tried to build a business again. I chose a business which I thought suitable for me. However, I got many barrier when I tried. But I made dua, wish Allah give me easiness to build a new business to fulfill my family need.
One day, someone suddenly offered me to take over his business, and ....... in cheap price!. I was so surprised because, I was not close with him, I didn't knew that he wanted to sell his business, I never told him about take over his business and even I never told him that I have interest to this business. But I realized this business was suitable with my current condition. So I took over his business although I must borrow money from my sister. Frankly, I really didn't have money in that time.
I believe, that was the answer of my dua.
The common question that appear in our mind when we want to establish a business is, what kind of business I should choose?. But unfortunately, many of us make mistake in answer this question. Instead of choose a business that suitable with our current condition, situation, and ability, we are deluded with our own 'dream'. Like the mistake that I've ever done. The business which I've planned before actually beyond my ability, and not suitable with my current condition and situation in that time. But I forced myself because I really want. That's why I got many barrier. And Alhamdulillah, later Allah showed me a suitable business for me.
So, sister. If you want to choose a business, it's better you make dua, wish Allah show you the most suitable business for you. If now you already run a business, you can still run your business. If your current business is suitable for you, Allah would give you a sign. If there is another business which more suitable for you, Allah would give you a sign too. And you must prepare yourself because this sign can come anytime.
About salah istikhara. Basically salah istikhara for choosing a business is same as salah istikhara for choosing a life-partner or choosing a school. The difference is only in dua that you say.