Money, of course! If you can have at least 1 year's living expenses saved up, or a day job/way to support yourself until your business becomes profitable, that makes things much easier.
The other thing I think is most needed is a very specific business plan. It should include specific facts about exactly who your target customers are, how much they typically spend on whatever you sell, when and where they buy it, where they spend their time, and how they can be reached (what media they pay attention to).
It should include a budget of how much your product/service will cost you to produce, including your own taxes, and with 10-20% more factored in for the inevitable extra costs you will run into.
Do as much research as you possibly can before making an outlay of cash for anything. You may find that your store would do better in another location, or your target customers want blue widgets and not red ones, and the time to find that out is before you sign the lease or buy the widgets.
My humble opinion, Mariette
