Conducting the discovery process
You are not an island. There are many parties that have an interest in the big picture. Some of them you have to make happy, e.g. your legal team, with others you want to determine what they need.
I will work with your stakeholders, internal across your organization, and external - partners or customers - so that everyone who needs to be involved is brought into the tent.
Common techniques I would use are interviews, group sessions and brainstormings, market research and competitive analysis. Know my motto: conversation over documentation!
Visualizing the product
We are visual creatures. Short of asking people for money, showing them a picture or a prototype that demonstrates your vision is a great test that you can always pass - though sometimes it takes several iterations to get it right.
We would pick a few key use cases and build an interactive playground where you learn more about how your idea would work in the real life.
Common tools used for such purpose are Axure or Balsamiq, and sometimes just plain HTML "dummy versions" that can be done in an afteroon with enough coffee and focus.
Mastering the backlog
Once the big ideas are clearly spelled out, it's time to get to work!
A backlog is a reservoir of work that will build your product. Agile teams commonly work with user stories, and that is my preferred format as well. In more traditional organizations, or whenever details must be verbalized in fine grain, the good old Use Cases will make the backlog.
I will address the common risk of "stale" and disconnected backlog and make sure that all dots are properly connected.
Making friends with developers
How to make a developer happy? Help him understand your intent and give him creative freedom to make it happen.
Armed with solid technical competence, I partner with developers who can do wonders on the web, mobile, or desktop. Conducting refinement sessions to introduce your ideas and prepare stories for development, subjecting the user stories to the stress-test of "what-if" scenarios, and mediating feedback that they give when they see a room for improvement, I guide the team on the road towards understanding.
During development, I will remain connected so that the final sign-off is a celebration of a job well done.
After the launch
Having implemented the right metrics, you will see how the product is performing and where it needs more attention. Nowadays, a product is never "done" until grand-fathered, so we'll have achieved a milestone, not an end-goal.
Managing the lifecycle of a live product has its specifics, and might use different processes in your organization, however we can still use many of the techniques above to iterate or pivot as required.