Definition:
User flow diagrams are similar to a Developers’ Task flow diagram. A task flow diagram shows all the possibilities a user could follow through your interface to complete a task. Where as UX designers do multiple User flow diagrams, typically one for each persona and/or a specific entry point.
 
When to use
On projects where your asked to maximise conversion rates.
 
Here are the steps I follow to make User flow diagrams…
 
Define entry point
The user is coming from:
1. Banner or Google advert.
2. Friend’s post on a social network.
3. Email newsletter.
4. Deep link that was surfaced by a search engine.
5. Link in news or a blog post.
6. Direct link (regular visitor).
 
Convert business goals into desirable user behaviour
Increase click-through rate = Make sure users know about this new feature and that it’s easy to use.
Pump up the viral coefficient = Encourage users who like and enjoy this feature to share it.
 
Define persona’s motivations
Find out motivations by answering these questions:
1. What needs or desires do your visitors have?
2. Which problem do they want to solve?
3. Why do they need it?
4. What qualities (about your product or service) are most important to them?
5. What are all the questions they have about the product?
6. What are their doubts or hesitations?
7. What information do they need to take action?
8. What’s their emotional hotspot to propel them towards taking action?
 
Match Persona’s motivations/needs to desirable user behaviour
Conversion will only happen when the final action provides value to both the user and the business.
 

 
Here is the steps I follow to improve User flow/conversion rates in a product…
 
Transparency
Have clear goals for users that help them understand where they’re going and each step they’ll take to get there.
 
Provide immediate feedback
Whenever users interact with the product, the UI needs to show them how they’re doing, and what’s going on.
 
Cater for expert users
Expert users want more efficiency. Do this by looking at ways to remove repetitive tasks.
 
Cater for serendipity
Allow for discovery. Expert users grow bored without serendipity. Look at improving discovery features.