Figure out the simplest version possible and build it. If you can't do it yourself, set a budget to get a prototype made and test it out with a handful of users.

From experience: determine whether this idea will be a side project or a serious business. If it's the latter, you'll want to read up on running a software business (I'd recommend Starting & Sustaining by Garrett Dimon: http://startingandsustaining.com).

Coming from someone who hasn't yet launched my own product, here is my plan:

1. Flesh out the idea - Right now its a fragile idea, start fleshing out all the details, get a document going. How will it work? Who is it for? Why would they want it? What are people using now? How is it better? How much is it worth to people? How will I make money off of this? How hard will it be to make?

2. Design, prototype, iterate - As designers we are at an advantage here, we can do everything but code it. So do that. Dont even think about code, just design the whole thing, iterate, and get a prototype going.

3. User feedback - get your prototypes and mocks in front of people. Ask the right questions, discover needs not opinions.

4. Find partners - Once you have the idea solid, the design solid, and mocks, you can now pitch your idea to like minded coders, business, and others who you think can help you.

5. Build a working prototype - Build the "Minimum lovable product" the main features, and enough UX and design to make it lovable but dont go crazy with added features.

6. Launch it, market it - Start a beta, get it in front of users, email websites with your marketing story about your product, leverage smaller sites covering you to get bigger sites to take notice.

7. Grow it - Once you have some users, grow it. See how its used or not used and polish your idea. If you need more money to grow, get funding. But if you can match your revenue with your growth you wont need it or as much of it.

8. ??? Profit? Sell? Retire? Make another? Might be good to start here too. Its going to be a hard road, where do you want to get off? How far will you take this?

Just had a product idea, what now?

Execution.

Bro, theres a whole bunch of validation and research that will really help you determine how to shape your product - so when you do launch your more inline with your potential users expectations. Below I'll going to focus on that as I wish I knew this when I started designing products:

Discovery: Talk to a small group of people (5-7 people), everyday day John and Jane people about they problems they have that your product aims to solve. This is about listening to people, understand their metal models, their priorities and workflows. This info will help you make decisions and prioritize features when it comes to actually designing and building your product.

Flesh out the idea but do it on pen and paper. I like the write a narrative about the product - i don't mean an elevator pitch, i mean the story of someone using your product (workflow).

EG: "Jane needs to transfer money to Greg because they just shared dinner together. Upon getting the bill Jane opens up App Name and adds Greg to her list of friends. On Gregs profile screen she taps the Transfer button, adds the amount and a message then hits send. Greg then receives a notification that Jane has sent him some cash."

This is super handy in seeing how it fits into peoples lives ( refer and the tasks involved with using your product. Write a few of these narratives for the different ways people can use your product and you start to get a better sense of whats involved and how to simplify the processes ....

Rough Prototype: Now sketch the shit out of this thing before going into hifi mockups.. Make it somewhat presentable in a pdf - seriously bare minimum possible. Arrange it in a workflow like the one above.

Test: Write a script that supports the workflow you have designed. You can basically use the narrative you have written already, but break it down into steps.

Go back to the people you interviewed at the start, maybe a couple of new people too, put the prototype infront of them and ask them how they would complete the first task. Then sit back and enjoy the ride. Go through each task one by one ... keep asking how they would do it on your prototype ... try not to help them ... if its not obvious to them ask them how they would have liked it, what were they expecting... Your looking for reactions, comments, how easily is each task completed, where they struggle, where are they delighted ... Your using a paper prototype so they wont get caught up in how it looks but they will tell you how it feels and how it matches their mental models.

Once you've interviewed a bunch of people you will see where your design sucks, where your design wins and you will have a better understanding of what your users expect and how they work.

Repeat: Go back modify your artwork, maybe next time comeback with some nicer looking sketches, work your way up into hifi artwork ... but when you do your layouts and workflows will be much more inline with the users expectations.

This is a quick look at user research and design testing. Basically this how you check your GPS on the way to creating an effective product.

Google Ventures is a good resource for learning this stuff.

Forget all the advice about coding anything.

Identify who you think the customers / users would be. List out all the assumptions surrounding your idea. Go talk to the customers / users about those assumptions.

And ask them to give you: Their time (to speak with you). Their reputation (share your idea with others). Their money (pre-sell the product).

Do this and you'll know the next step.

Zero code required.

It's super beta right now, but the concept of "I have an idea, now what?" is the focus of this web app: http://sprkapp.com/

I think I just had my first pivot and fixed some critical flaws by taking a different angle...

Thanks for the input so far everyone! Really helpful answers.

I'd actually disagree with the people who are saying that the next step is building it.

The first step is to figure out and write down what you think your business does, what it's customers are, what they value, etc.

I personally find the Business Model Canvas a nice tool for doing this http://www.businessmodelgenerati...

At this point you'll probably find that some of those ideas don't really work well as businesses. They might meet somebody's needs very well - but there aren't many people with the problem, or they can't afford to pay what it would cost to build a profitable business. So you can go look at some other ideas (or tweak your current one until it makes some kind of vague sense).

So at this point you have an idea of a business that seems to make sense.

What you have written down are not facts. They're assumptions - often informed ones - but assumptions nevertheless. The Lean Startup approach is based around repeatedly validating and refining the assumptions that you have about how your company works.

The absolute best way I know to validate assumptions about potential customers and their problems / needs is to go and watch/listen to them talk about their problems and needs.

Note; I am not talking about selling at this point. I'm talking about understanding and learning.

Reach out to friends of friends. Look to your personal network. If you've done a business model canvas look to the channels box and how you are thinking of finding clients. Do the clients that you're after go to certain kinds of events? If so go there yourself.

Again - not to sell but to listen. Ask them about their problems. Ask them to tell you stories about the issues they face. Listen - hopefully you should hear some of your assumptions verified. More likely you'll hear some new things that'll change some of your assumptions.

Once you're sure that you've identified who your customers are and the problems/needs that they have you'll be able to target them much more precisely. You'll know where they are, you'll know the problems they have and the way they internally describe those problems. The words they use to conceptualise them. The value that they'll get out of a solution. And so on.

With that you can start selling in a much more precise way, You'll know how to reach them. You know what language will appear.

Some of this will work well, others not so well. This is learning too. Use it to tweak and target your sales and product pitch.

Repeat.

Grab a like-minded friend or colleague who has the skills to code up the idea.

Break it down to it's simplest form to something that's achievable in your spare-time.

Do the UX and designs for your buddy so he can plan the effort on his side. Make sure the flow is laid out.

Help your buddy in anyway possible to make the MVP easier to develop. Find frameworks, bug fixes on Stack Overflow, 3rd party services etc.

Wait...

Launch!

A few others have mentioned doing user research etc... but just build it. The experience will make you a better designer plus you'll have a product under your belt.

If people love it then great, if not, then you have something under your name which will give you more credibility with investors when you make your next thing.

Contact me at gianluca@fabrica.io

I will help you building it.