You start by making sure your business idea is really as great as you think it is. One of the leading causes of failure for startups is that there was no actual market for their products. It doesn’t matter how great the startup founders think an idea is – the only thing that matters is how many customers think it’s a great idea.
Ideally, you would find at least 100 potential real customers who would buy your product today if it existed. Not friends and family who will tell you what you want to hear, but qualified buyers who are tripping over themselves to get your product and can’t wait until it comes to market.
In essence, this is what Kickstarter is really about: potential customers who are so excited about an idea that they are willing to pre-pay for a product that doesn’t yet exist. When you have that kind of interest in your product, funding your startup is a lot easier.
The next step is to do some basic business planning, and make sure you’ve thought through the business step by step. There are plenty of simple basic business planning guides online.
Keep the first draft simple: Imagine that you’re telling someone a story of what your first year in business will look like. Describe your product or service, what will it cost to make it, how will you make/deliver it, what equipment do you need to get started, how many employees will you need and when, what will you charge for it, who is your customer, how will you find them, how will they find you, timelines and milestones, etc.
Somewhere in there you need to build a sample income/expense table that shows how much cash you’ll need each month (rent, supplies, payroll, etc.) and where it will come from (startup funds, sales).
Once you have a draft, I would work with a startup coach, local entrepreneur network, or an experienced business mentor to start flushing out more details and challenging assumptions in your plan. You’ll also want to start building out a prototype of your product or service to help validate your ideas and test assumptions. (Bernie Klinder’s answer to What is the process to test the viability of a business idea?) Getting an actual product/service into the hands of early adopters who are willing to give you feedback is crucial and will enable you to make needed changes before you spend all of your startup funds.
Once you have a working product on a small scale, and lots of waiting customers, working out the details to launch should be fairly straight-forward.
Hope this was helpful. Good luck!