Following is the "summarized" process that you should follow to build any Startup Business:
1. Find the Problem (idea) & think of its Solution (Product). Any innovative idea will work too.
Eg: The birth of UBER.
2. Do the Market Research & get Statistics as it will help you to take a decision.
Eg: You must not enter into the market until & unless you have something extraordinary to put in.
3. Build a PoC / Minimum Viable Product (Prototype).
Eg: Remember UBER started off with just 3 cabs in the New York City.
4. Get the Initial Traction from the MVP (Prototype) to validate.
Eg: Get the feedback and analyze it, fix it, refine it until desired acceptance is seen.
5. Work on your Product Positioning (Along with PoC / MVP) strategies.
Eg: One of the great example of an improper product positioning is the Apple's Newton PDA .
6. Build an excellent Go To Market (GTM) Strategy to put a footprint of your product.
Eg: Research how some great companies got very heavy traction initially.
7. Frame & Work on your Sales & Marketing strategies in order to gain customers and momentum.
Eg: Research why Some companies invest nothing and some invest millions $$
8. Approach to Investors but don't rely on them. Investment process takes at least 3-6 months.
A lot happens and things to be worked before actually executing the idea. Value the Time & the Money and you will get the good returns.